Add logging for modify share and custom action clicks

Just a regular UiEvent log for modify share. Include position
information for custom actions (*just* the position within the custom
action set, ignoring other system actions that may be within the display
container).

Bug: 265504112
Test: atest ChooserActivityLoggerTest
Test: atest ChooserActivityFactoryTest
Change-Id: If64db5c1afccf6571d23395624d6ffbbef677188
5 files changed