Revert "Revert "Enable R8 full mode by default for apps""

This reverts commit ba283992.

Reason for revert: Resolved associated test/build failures

Bug: 215530220
Test: atest BluetoothInstrumentationTests
Test: atest RkpdAppGoogleUnitTests
Change-Id: I27ad6a4f910fa8d48a3dc122c7542f8d7667de5a