Refrain from persisting shortcuts into AppSearch in low end device

As observed in b/220133968, on low-end devices, persisting shortcut into
AppSearch on a background thread introduces 50ms delay on app start time.

Given that there isn't a clear product roadmap for such feature to work
on Go devices, we will disable the integration until we have a concrete
demand for such feature that justfies the performance cost on low end
devices.

Bug: 220133968
Test: atest CtsShortcutManagerTestCases
Change-Id: I10339b3b3211b20994a8bca581504ea609b985ee
Merged-In: I10339b3b3211b20994a8bca581504ea609b985ee