Deserialize a native_handle safely.

Actually verify that the native_handle size that we receive
matches with the number of integers and file descriptors
enclosed within.

Bug: 120084106
Test: builds, boots
Change-Id: Ibc52170fcfc59d4f0354b5df4b9745b58ab244fe
(cherry picked from commit 5ad4ab1189dbf3fbee6c8c75b30f37fd9db40ed9)