Surface: Allow nullable IGBPs when unparceling a Surface

We will write a null IGBP, so we shouldn't error out when reading one;
leave semantics of that to higher-level code.

Test: No camera crash after lots of front-back camera switches
Bug: 31373143
Change-Id: I5f7cf7489aca721057c5731e3a79cf6f8f260774
1 file changed