Add flag guard to hover actions in TouchInteractionService.

Flag: ACONFIG com.android.launcher3.enable_cursor_hover_states NEXTFOOD
Test: Manual.
Bug: 306745595
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:8bcf485ac4c61290facfcb28dadee7535901a42c)
Merged-In: I74818f517b84c4aba8a7dd4a77397495595bbef5
Change-Id: I74818f517b84c4aba8a7dd4a77397495595bbef5