[Safer intents] Credentials

To avoid implicit intents, make intents launch explicitly.

Bug: 323061508
Test: build
Change-Id: I236b6214e761574c82a81b4a7e068f617eae5e9d

src/com/android/settings/MonitoringCertInfoActivity.java

@@ -117,6 +117,7 @@ public class MonitoringCertInfoActivity extends Activity implements OnClickListe
     @Override
     public void onClick(DialogInterface dialog, int which) {
         Intent intent = new Intent(android.provider.Settings.ACTION_TRUSTED_CREDENTIALS_USER);
+        intent.setPackage(getPackageName());
         intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TOP);
         intent.putExtra(TrustedCredentialsSettings.ARG_SHOW_NEW_FOR_USER, mUserId);
         startActivity(intent);

src/com/android/settings/security/CredentialStorage.java

@@ -139,6 +139,7 @@ public final class CredentialStorage extends FragmentActivity {
             }
 
             final Intent installIntent = new Intent(ACTION_INSTALL)
+                    .setPackage(getPackageName())
                     .setFlags(Intent.FLAG_ACTIVITY_FORWARD_RESULT)
                     .putExtras(bundle);
             startActivityAsUser(installIntent, new UserHandle(dstUserId));

src/com/android/settings/security/InstallCaCertificateWarning.java

@@ -41,6 +41,8 @@ import com.google.android.setupdesign.util.ThemeHelper;
  */
 public class InstallCaCertificateWarning extends Activity {
 
+    private static final String CERT_INSTALLER_PACKAGE_NAME = "com.android.certinstaller";
+
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -79,6 +81,7 @@ public class InstallCaCertificateWarning extends Activity {
         return v -> {
             final Intent intent = new Intent();
             intent.setAction(Credentials.INSTALL_ACTION);
+            intent.setPackage(CERT_INSTALLER_PACKAGE_NAME);
             intent.putExtra(Credentials.EXTRA_CERTIFICATE_USAGE, Credentials.CERTIFICATE_USAGE_CA);
             startActivity(intent);
             finish();