Restore deleted chooser API flags.

They were removed in flag cleanup, but per
go/android-flags-guidelines#how-to-delete-a-flag they should not have
been removed because they are exported.

Bug: 354089228
Test: N/A
Flag: EXEMPT just restoring definitions.
Change-Id: I2b4f40196e32c9b9c93aeb119903e480155abd0d