Only reinflate bouncer after rotation if flag enabled

Re-inflating on orientation change is now guarded by the unreleased flag "lockscreen.enable_landscape", b/293252410, so the behaviour is back to the usual when this flag is off.

New tests to cover this case.

Bug: 295603468
Test: PinBouncerLandscapeLayout, PinBouncerPortraitLayout, PinBouncerLargeLayout
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:ad9db9cfe885e2a3b218815b4ac69741a5d2f536)
Merged-In: Ida08cc6e5c022a457e0d603ab75424d563dc0538
Change-Id: Ida08cc6e5c022a457e0d603ab75424d563dc0538