Fix library order in class loader context to agree with PackageManager.

PackageManager adds compatibility libraries for different SDK versions
in descending order, and Soong should do the same.

Bug: 132357300

Test: lunch aosp_cf_x86_phone-userdebug && m \
  && launch_cvd \
  && adb wait-for-device \
  && adb logcat | grep -E 'ClassLoaderContext [a-z ]+ mismatch'

  [no messages "ClassLoaderContext classpath element mismatch"]

Change-Id: Ib1d981808ae4022b2c6e73f407a003e8b8e9c7d6