Add ACTION_EPHEMERAL_RESOLVER_SETTINGS

This Intent will be used in Settings to show the settings UI for the
Ephemeral resolver. Settings can get the correct component to send the
Intent to by calling
PackageManager.getInstantAppResolverSettingsComponent

Bug: 35918998
Test: Boots
Change-Id: I0edcf85704f2c19e0ee27f91b6ef057d52e32778