Fix idmap2 uninitialized variables

Some primitives were not initialized to a default value causing
--ignore-overlayable and --verbose to default to true.

Bug: 148181123
Test: idmap2_tests
Change-Id: If87ba76b7d24803f46b71ef36befa12f25916680
Merged-In: Ic9dbd3e9a768beb39ac677ff294b0fca5ee8f9d2