Add min_sdk_version rule to allow use from AppSearch apex.

The dependency was already allowed in apexes, but presubmits were
failing on it due to lack of min_sdk_version.

Bug: 218419277
Test: Builds; passes CTS tests
Change-Id: I7577639e35f1f5a8c20695e2600e0fad2ec5938f
1 file changed