Safecty checker improvements on DevicePolicyManagerService.

- Include mSafetyChecker on dump().
- Change OneTimeSafetyChecker so it's disabled after any operation.
- (Conditionally) log the mSafetyChecker used.

Bug: 172376923

Test: adb shell dumpsys device_policy | grep mSafetyChecker
Test: atest CtsDevicePolicyManagerTestCases:DeviceOwnerTest#testDevicePolicySafetyCheckerIntegration_allOperations,testDevicePolicySafetyCheckerIntegration_isSafeOperation,testDevicePolicySafetyCheckerIntegration_unsafeStateException \
  CtsDevicePolicyManagerTestCases:ProfileOwnerTest#testDevicePolicySafetyCheckerIntegration_allOperations,testDevicePolicySafetyCheckerIntegration_isSafeOperation,testDevicePolicySafetyCheckerIntegration_unsafeStateException

Change-Id: Ife936cea89c6e21a56454766ecb4b29b652bd584

services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java

@@ -1138,6 +1138,11 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
 
     @Override
     public boolean isSafeOperation(@OperationSafetyReason int reason) {
+        if (VERBOSE_LOG) {
+            Slog.v(LOG_TAG, "checking isSafeOperation("
+                    + DevicePolicyManager.operationSafetyReasonToString(reason)
+                    + ") using mSafetyChecker " + mSafetyChecker);
+        }
         return mSafetyChecker == null ? true : mSafetyChecker.isSafeOperation(reason);
     }
 
@@ -9172,8 +9177,7 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
         pw.printf("mIsWatch=%b\n", mIsWatch);
         pw.printf("mIsAutomotive=%b\n", mIsAutomotive);
         pw.printf("mHasTelephonyFeature=%b\n", mHasTelephonyFeature);
-        String safetyChecker = mSafetyChecker == null ? "N/A" : mSafetyChecker.getClass().getName();
-        pw.printf("mSafetyChecker=%b\n", safetyChecker);
+        pw.printf("mSafetyChecker=%s\n", mSafetyChecker);
         pw.decreaseIndent();
     }
 

services/devicepolicy/java/com/android/server/devicepolicy/OneTimeSafetyChecker.java

@@ -78,9 +78,9 @@ final class OneTimeSafetyChecker implements DevicePolicySafetyChecker {
         Slog.i(TAG, "notifying " + reasonName + " is inactive");
         dpmi.notifyUnsafeOperationStateChanged(this, reason, false);
 
-        Slog.i(TAG, "returning " + reasonName
-                + " and restoring DevicePolicySafetyChecker to " + mRealSafetyChecker);
-        mService.setDevicePolicySafetyCheckerUnchecked(mRealSafetyChecker);
+        Slog.i(TAG, "returning " + reasonName);
+
+        disableSelf();
         return reason;
     }
 
@@ -89,6 +89,7 @@ final class OneTimeSafetyChecker implements DevicePolicySafetyChecker {
         boolean safe = mReason != reason;
         Slog.i(TAG, "isSafeOperation(" + operationSafetyReasonToString(reason) + "): " + safe);
 
+        disableSelf();
         return safe;
     }
 
@@ -96,4 +97,16 @@ final class OneTimeSafetyChecker implements DevicePolicySafetyChecker {
     public void onFactoryReset(IResultReceiver callback) {
         throw new UnsupportedOperationException();
     }
+
+    private void disableSelf() {
+        Slog.i(TAG, "restoring DevicePolicySafetyChecker to " + mRealSafetyChecker);
+        mService.setDevicePolicySafetyCheckerUnchecked(mRealSafetyChecker);
+    }
+
+    @Override
+    public String toString() {
+        return "OneTimeSafetyChecker[id=" + System.identityHashCode(this)
+                + ", reason=" + operationSafetyReasonToString(mReason)
+                + ", operation=" + operationToString(mOperation) + ']';
+    }
 }