Cleanup CL to prepare for single user-confirmation dialog change

This CL attempts to cleanup the code in PIA, to fix potential animation
glitches and smoothens the install flow, visually

Bug: 319320680
Test: Manual. Install an APK and check for visual glitches
Change-Id: Ie571193d2028ae0a7298eb148a4a986c3b52c4aa
5 files changed