Create the filegroup to collect cert files for otatools.zip

Create "soong_generated_otatools_package_filegroup" to collect the cert
files from following folders:
- //build/make/target/product/security
- //device
- //external/avb/test/data
- //packages/modules
- //vendor

Bug: 395988167
Test: m dist otatools-package-temp
Change-Id: I578ee475d1f3ae873d0c1184df353e67c5fbb6fd