Remove enabled flag use_visible_requested_for_process_tracker

Bug: 414269923
Flag: EXEMPT flag removal
Test: BackgroundActivityLaunchTest
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:01358ba370c7fe020dfbe4328ae65ac3997de6f5
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:68417f0d05b24a0bd959171bca34cd218b42fa40
Merged-In: I61169d7adafbb8c43a9a1e97fe963cfe50bb90ad
Change-Id: I61169d7adafbb8c43a9a1e97fe963cfe50bb90ad
3 files changed