Simplify the construction of class loader contexts for system server jars.

This reworks CL https://r.android.com/1180134 as follows:

1) Do not reorder the list of system server jars passed from Make to
  Soong via the product variable PRODUCT_SYSTEM_SERVER_JARS. This means
  that for some products the order of jars on the system server
  classpath may be non-optimal: a jar X that depends on Y may be
  dexpreopted before Y, so that all references to the classes and
  methods from Y wil be unresolved.

  Unfortunately for such products, fixing the order is not a simple
  matter of rearranging their PRODUCT_SYSTEM_SERVER_JARS, because the
  conflicts may arise when the product-specific variable gets merged
  with the common variable.

2) As a consequence of 1), do not add artificial dependencies between
  system server jars: this is now impossible, as it would create
  circular dependencies for those products that have non-optimal order
  of jars.

3) Copy dex files for system server jars to a predefined build location.
  This is necessary because at the time when Soong generates class
  loader context for k-th jar, it needs to know the paths to jars 1 ..
  (k-1), and it might have not processed those jars yet (so Soong can't
  query the paths from the modules).

  This approach is similar to the way Soong handles bootclasspath jars.

4) Do not exclude from dexpreopting system server jars that are not
  Soong modules (those that are Make modules). The previous CL excluded
  them because Make modules do not have ModuleContext. But it turns out
  that ModuleContext is not necessary, as all the information is passed
  via the dexpreopt config.

Test: aosp_walleye-userdebug boots and there are no messages in the
  logcat regarding class loader context mismatch:

  $ adb logcat | grep 'mismatch'
  # empty

Test: Class loader contexts in the oat files for system server jars
  match expectations:

  $ oatdump --oat-file=out/target/product/walleye/system/framework/oat/arm64/com.android.location.provider.odex 2>/dev/null | grep '^classpath'
  classpath = PCL[]
  $ oatdump --oat-file=out/target/product/walleye/system/framework/oat/arm64/services.odex 2>/dev/null | grep '^classpath'
  classpath = PCL[/system/framework/com.android.location.provider.jar*1989208671]
  $ oatdump --oat-file=out/target/product/walleye/system/framework/oat/arm64/ethernet-service.odex 2>/dev/null | grep '^classpath'
  classpath = PCL[/system/framework/com.android.location.provider.jar*1989208671:/system/framework/services.jar*4040443083:/system/framework/services.jar!classes2.dex*2210087472]

Test: The phone boots and logcat has no scary messages related to
  class loader contexts:

  $ lunch aosp_walleye-userdebug && m
  $ adb reboot bootloader && fastboot flashall -w && adb wait-for-device
  $ adb root
  $ adb shell stop
  $ adb logcat -c
  $ adb shell setprop dalvik.vm.extra-opts -verbose:oat
  $ adb shell start
  $ adb logcat | egrep -io 'system_server: .*load.*/system/framework.*'
  system_server: Loading /system/framework/oat/arm64/com.android.location.provider.odex with executable: 0
  system_server: Successfully loaded /system/framework/oat/arm64/com.android.location.provider.odex with executable: 0
  system_server: Loading /system/framework/oat/arm64/services.odex with executable: 0
  system_server: Successfully loaded /system/framework/oat/arm64/services.odex with executable: 0
  system_server: Loading /system/framework/oat/arm64/ethernet-service.odex with executable: 0
  system_server: Successfully loaded /system/framework/oat/arm64/ethernet-service.odex with executable: 0
  system_server: Loading /system/framework/oat/arm64/wifi-service.odex with executable: 0
  system_server: Successfully loaded /system/framework/oat/arm64/wifi-service.odex with executable: 0
  system_server: Loading /system/framework/oat/arm64/com.android.location.provider.odex with executable: 1
  system_server: Successfully loaded /system/framework/oat/arm64/com.android.location.provider.odex with executable: 1
  system_server: Loading /system/framework/oat/arm64/services.odex with executable: 1
  system_server: Successfully loaded /system/framework/oat/arm64/services.odex with executable: 1
  system_server: Loading /system/framework/oat/arm64/ethernet-service.odex with executable: 1
  system_server: Successfully loaded /system/framework/oat/arm64/ethernet-service.odex with executable: 1
  system_server: Loading /system/framework/oat/arm64/wifi-service.odex with executable: 1
  system_server: Successfully loaded /system/framework/oat/arm64/wifi-service.odex with executable: 1
  system_server: Loading /system/framework/oat/arm64/com.android.location.provider.odex with executable: 1
  system_server: Successfully loaded /system/framework/oat/arm64/com.android.location.provider.odex with executable: 1

Bug: 141785760
Bug: 140451054
Bug: 148944771
Bug: 147017252

Change-Id: I33c4087f8bfacd0ecb89877aa150b75360d06710