Replace ENABLE_LAUNCHER_BR_METRICS flags with fixed aconfig flag.

This is necessary because the value of the read-write flag will not be updated in time for backup/restore.

Bug: 307527314
Test: compiles
Flag: ACONFIG ENABLE_LAUNCHER_BR_METRICS_FIXED TEAMFOOD
Change-Id: I67a1a820734d8881b3ed5be4a1f2f1556e6e4704
5 files changed