Fixed null callback issue
Fixed the vendor data/network service non-responsive
issue. The callback binder passed from frameworks
might be GC'd so that vendor data/network service skipped
calling the callback. This eventually caused data
connection state machine messed up.
Fixed by turning the weak refernce to the callback into
a strong reference. This ensure the binder alive when
vendor service needs to invoke the callback.
Test: Telephony sanity tests
Bug:
139076980
Merged-In: Ica0b7b810ffd5416ffd1b2b61f7ebc4af0dcb8ce
Change-Id: Ica0b7b810ffd5416ffd1b2b61f7ebc4af0dcb8ce
(cherry picked from commit
09ef1cb126ee59dcb4eacfc3a8afefcb0f991945)