Have a new API to get private DNS mode

- Expose PRIVATE_DNS_MODE_OFF, PRIVATE_DNS_MODE_OPPORTUNISTIC and
PRIVATE_DNS_MODE_PROVIDER_HOSTNAME for external users.
- Since PRIVATE_DNS_DEFAULT_MODE_FALLBACK might be changed from
release to release, so it cannot be exposed as a system API.
Remove PRIVATE_DNS_DEFAULT_MODE_FALLBACK and have a new API -
getPrivateDnsMode() for users to get the private DNS mode instead.

Bug: 172183305
Test: atest FrameworksNetTests CtsNetTestCases
Change-Id: I02a1e91b4eafb5f5df3eada1c07b99849a050c3c
Merged-In: I02a1e91b4eafb5f5df3eada1c07b99849a050c3c

1 files changed, 2 insertions, 4 deletions

diff --git a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
index 6badafa34dfd..374abd6a6f85 100644
--- a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
+++ b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
@@ -15621,10 +15621,8 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
 
         Objects.requireNonNull(who, "ComponentName is null");
         enforceDeviceOwner(who);
-        String currentMode = mInjector.settingsGlobalGetString(PRIVATE_DNS_MODE);
-        if (currentMode == null) {
-            currentMode = ConnectivityManager.PRIVATE_DNS_DEFAULT_MODE_FALLBACK;
-        }
+        final String currentMode =
+                ConnectivityManager.getPrivateDnsMode(mContext.getContentResolver());
         switch (currentMode) {
             case ConnectivityManager.PRIVATE_DNS_MODE_OFF:
                 return PRIVATE_DNS_MODE_OFF;