Revert "Removing flag com.android.server.am.limit_priority_scope from trunk_staging."

This reverts commit 915f7917b2a5ca3f48361269ff36b6c9b82ea924.

Reason for revert: Reverting this change per wear performance process as  this is causing a performance regression. Check bug b/378423147 for more details. 

Change-Id: I012c7f9bb2aa12d9ffcec4363f05a2616ad5a05b