idmap2: support Lookup for arrays

Lookup of array resource in idmap2 would result in an error.
The reason was that on AssetManager2::GetValue call bags were
not taken into consideration.

Acquire the bag as well and traverse through it to fetch all
its values.

Bug: 134426097
Test: run `adb exec-out lookup` on a known array resource
Change-Id: Ife066154e74d2ee8bd7b273030e75d8448558437
Signed-off-by: Zoran Jovanovic <zoran.jovanovic@sony.com>