[ECM] Do not restrict packages based on installer

Previously, we had a business rule was that if a package is installed
by a non-allowlisted installer, we would not trust the package.

However, we're changing this requirement. Now, a package's
trustworthiness won't depend on which app installed it.

LOW_COVERAGE_REASON=327533775
Bug: 327469699
Test: atest CtsPermissionUiTestCases:android.permissionui.cts.EnhancedConfirmationManagerTest
Change-Id: Ie9c1b48f19c719b931724a044d06da27f95a004a