Enable bubbles home gesture by default

Update feature flag for bubbles home gesture handling to be on by
default.

Bug: 170163464
Test: manually verified that home gesture feature is enabled on a fresh
build
Test: atest PlatformScenarioTests:android.platform.test.scenario.sysui.bubble

Change-Id: Ifd5492a6fc75b0600a3f7a716711bb6de8aa70c3