Skip nav button animation in gesture nav mode

- Also removed unused rotation button code
- Skip adding certain property holders in phone mode
- Update FLAG_SMALL_SCREEN value from isPhoneButtonNavMode to isPhoneMode, so that it's more aligned with what the name suggests (it shouldn't affect the functionality regardless as the view is invisible in small screen)

Based on https://b.corp.google.com/issues/361593564#comment4

Bug: 361593564
Test: manual
Flag: EXEMPT bugfix
Change-Id: I1de7fa061a6c6aba9f949a0bcf8cfced84273e3f