New management API for making backups mandatory.

Let the device owner make backups with a chosen backup
transport mandatory.

BUG: 64012357
Test: make RunFrameworksServicesRoboTests
Test: manually together with the corresponding GmsCore change.
Test: cts-tradefed run cts -m CtsDevicePolicyManagerTestCases --test
com.android.cts.devicepolicy.DeviceOwnerTest#testGetAndSetMandatoryBackupTransport
Test: cts-tradefed run cts -m CtsBackupHostTestCase --test
android.cts.backup.BackupDeviceOwnerHostSideTest#testMandatoryBackupTransport

Change-Id: I9bfae5799beae3459659e697813b75a9b508ae55
diff --git a/core/java/android/app/admin/IDevicePolicyManager.aidl b/core/java/android/app/admin/IDevicePolicyManager.aidl
index 7154053..9cdd1f8 100644
--- a/core/java/android/app/admin/IDevicePolicyManager.aidl
+++ b/core/java/android/app/admin/IDevicePolicyManager.aidl
@@ -359,6 +359,8 @@
 
     void setBackupServiceEnabled(in ComponentName admin, boolean enabled);
     boolean isBackupServiceEnabled(in ComponentName admin);
+    void setMandatoryBackupTransport(in ComponentName admin, in ComponentName backupTransportComponent);
+    ComponentName getMandatoryBackupTransport();
 
     void setNetworkLoggingEnabled(in ComponentName admin, boolean enabled);
     boolean isNetworkLoggingEnabled(in ComponentName admin);