Set mDataSize properly in appendFrom mDataSize only increases if we end up with mDataPos greater than mDataSize. Test: binder_parcel_fuzzer Bug: 438098181 Flag: EXEMPT bug fix (cherry picked from https://googleplex-android-review.googlesource.com/q/commit:ab883e120ae18ef93a4c6f17c05a14218da5118e) Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:48ab33eba1eff4afc1c2d72dea846680f70efad2 Merged-In: I932ad50627d15452f67b39bd410d666dc8e70a42 Change-Id: I932ad50627d15452f67b39bd410d666dc8e70a42