Change the default package license to Apache-2.0 and remove the Android.mk.

The Android.mk contains license declaration for aapt2_result only, and with this change that declares the license of the package precisely the
Android.mk is not needed any more.

Bug: 322285259
Test: CIs
Change-Id: Ie4b82686cc72d07b1c75016ede6f3c7c53816e83
2 files changed