Prevent shade from opening while GH is in transition

Only pass the touch events through when we are idle on the hub.

Flag: com.android.systemui.restrict_communal_shade_to_when_idle
Bug: 446291379
Test: atest ShadeTouchHandlerTest
Test: manually by enabling flag and attempting to open shade while
transitioning to hub
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:ff43a4722f12808835ccffc85472e8dcbb9a8cd7
Merged-In: I6b1ecbafa32dd5c0194ae648b8487f93f6681c12
Change-Id: I6b1ecbafa32dd5c0194ae648b8487f93f6681c12