Fix error handling in CompressJob

If a new archive cannot be created, CompressJob.setUp() now returns
false instead of throwing a NullPointerException.

Bug: 439736151
Flag: EXEMPT fixing existing bugs
Test: atest DocumentsUIGoogleTests:com.android.documentsui.services

Change-Id: Id1e196edc9546db2cbffb3c59d5a6d3a5401444f