Fix CTS: MixedManagedProfileOwnerTest#testDelegatedCertInstaller failure

Cause: isKeyguardSecure api change KeyguardManager.isSecure()
to observe work profile in ag/1026084 (b/28666104). Only when
managed profile has password and work challenge,
KeyguardManager.isSecure() returns true.

Convert the activity into receiver as activity can't bypass
work challenge even using showForAllUser flag, b/28935539

BUG: 28888625
Change-Id: I3d995be3452a1339116022477d6c8f2d32dc30a1
5 files changed