[35/n] Extract AppCompatDisplayInsets from ActivityRecord

As first step we move the CompatDisplayInsets class to the
new AppCompatDisplayINsets class.

Flag: EXEMPT refactor
Bug: 360865550
Test: atest WmTests:ActivityRecordTests
Test: atest WmTests:SizeCompatTests
Test: atest WmTests:TaskTests
Test: atest WmTests:TransparentPolicyTest

Change-Id: Iaf1a85c9bae6673f9dd4e93ffc81a5f4ff9bd552