Create a Strict Mode violation for Background Activity Launch

In the recent Android releases we have hardened the BAL restrictions to reduce the potential for malware development.
In strict mode we offer a tool for developers to use during their app development to detect potential background activity launches that would be blocked.

Flag: com.android.window.flags.bal_strict_mode
Bug: 324089586
Test: atest StrictModeTest
Change-Id: I87851e221bd0ebfeb08ad4921f72dd1f7a7b0228