Add CharSequence into ignorable imports

java.lang.CharSequence is a built-in aidl type, so actually it doesn't
need to be imported explicitly. But for some legacy use case, added it
into allowlist

Bug: 169193089
Test: try "import java.lang.CharSequence"
Change-Id: Ia22ee4394a7394060233fcc7034d80241f8929b2
Merged-In: Ia22ee4394a7394060233fcc7034d80241f8929b2
1 file changed