Opt out of predictive back for activities with custom onBackPressed handling

This CL ensures that some framework activities with custom back handling (onBackPressed overridden) remain opted-out of predictive back.

Predictive back will be enabled by default starting with Android B (and targetSDK>=36).

Bug: 376407910
Test: presubmit
Flag: com.android.window.flags.predictive_back_default_enable_sdk_36
Change-Id: Idb0a2446919bbfb80fcb895772cdff648211066c