Add dependencies on org.apache.http.legacy where needed

Incorporates two main changes:
* Stops statically including the org.apache.http.legacy library. That library is
  a stubs library so it makes no sense to statically include it.
* Adds uses-library declaration for org.apache.http.legacy to those packages
  that depend on org.apache.http.legacy, either directly or transitively.

The following change descriptions were generated automatically and so
may be a little repetitive. They are provided to give the reviewer
enough information to check the comments match what has actually been
changed and check the reasoning behind the changes.

* packages/StatementService/AndroidManifest.xml
    Added <uses-library> for org.apache.http.legacy to ensure classes
    are provided at runtime. It is not treated as optional as the
    application is not intended to be run on a version that does not
    provide the library, i.e. its minSdkVersion is >= M (23)

Bug: 18027885
Test: m -j32 droid && adb reboot bootloader && fastboot flashall -w
Change-Id: I96e467a1916bd6c3f4b33164fae940f322fef80c