Should only call the new callback Also check null on the service side Bug: 325544756 Test: atest WifiManagerTest (cherry picked from https://googleplex-android-review.googlesource.com/q/commit:0ecd3aea171d62e82a234698114d5ad8df1074ac) Merged-In: I4e1c0d8dce4fd6d1be51653f776843a66cb7ec85 Change-Id: I4e1c0d8dce4fd6d1be51653f776843a66cb7ec85