PasswordPolicy.getMinMetrics PIN

* If the password quality is NUMERIC
  or NUMERIC_COMPLEX, the credential
  type should be CREDENTIAL_TYPE_PIN

Bug: 184103377
Test: atest com.android.server.devicepolicy.PasswordPolicyTest
      atest android.app.admin.PasswordMetricsTest
      atest com.android.cts.devicepolicy.MixedManagedProfileOwnerTest
      atest com.android.server.devicepolicy.DevicePolicyManagerTest
      atest com.android.cts.devicepolicy.ManagedProfilePasswordTest
      make RunSettingsRoboTests -j ROBOTEST_FILTER=com.android.settings.password
      CtsVerifier > Device owner tests > policy transparency test
      > set password quality
Change-Id: Ibad35d22c34b6cd9ed34b2e671b38503becd7da5