Adds ContentObserver for Swipe Up enabled setting

Registers a ContentObserver to handle Swipe Up gesture enable/disable
changes from Settings App. Also provides a static method to get the
current state of settings for the Swipe Up feature.

Bug: 77549883
Test: Manual Test
Change-Id: I5aa13cebdcb78be4869e8a5ae7f570490c8ac05c
2 files changed