Add DomainVerificationShell and boot broadcast

Support for mutating internal state using pm shell commands.

Also wires up the boot broadcast now that the ability to verify all
unverified packages has been added.

Exempt-From-Owner-Approval: Already approved by owners on main branch

Bug: 163565712

Test: TODO

Change-Id: I809436c6b8ff04cdc68430303859d2d7f40d9557