When feature flag is enabled for AllInOneTetherSettings, implicit intent
to TetherSettingsActivity or WifiTetherSettingsActivity should launch
AllInOneTetherSettings fragement. The behavior won't change when flag is
disabled.
Bug: 149590956
Test: make RunSettingsRoboTests ROBOTEST_FILTER=CodeInspectionTest,
built and flashed to device. When flag disabled, long clicking on
Hotspot Tile will go to TetherSettings fragment. When flag enabled,
long clicking on Hotspot Tile will go to AllInOneTetherSettings
fragment.
Change-Id: Iffdaacde000fb58c7e54406522fac0541cabf7fc
aaf5fe5af2