Fix shortcut icons on O

Use IconCompat to create the adaptive icons. When attaching the icon
to the result intent for ACTION_SHORTCUT on >= O use
IconCompat.addToShortcutResult(). Otherwise continue to manually add
it for pre-O.

Test: Manually verified creating shortcuts on N M and O still work as
expected.

Bug: 62112388
Change-Id: I07f5a8ffd1f49edb4c21aaa572b42f641111e798