Handle the visibility of sdk sandbox uids

Sdk sandbox processes have the following visibility rules:

1. Sdk sandbox process should be visible to itself
2. Sdk sandbox process should be visible to the corresponding client app
3. Sdk sandbox process shouldn't be visible to anything else

On top of that handle the NPE in the
ComputerEngine.shouldFilterApplication by treating null
PackageStateInternal the same way it is treated in case the calling uid
belongs to the instant app, which is to pretend that null application
exists and that it shouldn't be visible to sdk sandbox.

Bug: 236162773
Test: atest SdkSandboxInprocessTests
Change-Id: Ic2583610f55c36169f9abb35b58a0ab60884a312
Merged-In: Ic2583610f55c36169f9abb35b58a0ab60884a312
1 file changed