Add "com.android.btservices" to 'apex_available' property of "android.os.flags-aconfig-java-export"

Bug: 344915071
Flag: key_missing_as_ordered_broadcast
Test: mma -j68
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:5fd64d5683de1ddf03420a9c7f50d9e7489cd1a1)
Merged-In: Ifc77a4fc888847e4b03a2b6ed66d2fac0f6d6f55
Change-Id: Ifc77a4fc888847e4b03a2b6ed66d2fac0f6d6f55