Fix error handling in CompressJob

When the destination archive cannot be created or acquired, ensure that
CompressJob cleans up correctly.

Add some @NonNull annotations.
Add some comments.

Bug: 439736151
Flag: EXEMPT fixing existing bugs
Test: atest DocumentsUIGoogleTests:com.android.documentsui.services.CompressJobTest
Change-Id: I1299027053f34d5f91ab5e9ec7d9c126b140d0c2