Fix NullPointerException when telephony does not return ModemActivityInfo

Bug: 342865877
Test: atest FrameworksServicesTests PowerStatsTests
Test: atest --host FrameworksServicesTestsRavenwood PowerStatsTestsRavenwood
Flag: com.android.server.power.optimization.streamlined_connectivity_battery_stats
Change-Id: Iaabbf99a672e2154d2927cc58aeb97b63d6d6488

services/core/java/com/android/server/power/stats/MobileRadioPowerStatsCollector.java

@@ -195,6 +195,9 @@ public class MobileRadioPowerStatsCollector extends PowerStatsCollector {
             return null;
         }
 
+        Arrays.fill(mPowerStats.stats, 0);
+        mPowerStats.uidStats.clear();
+
         collectModemActivityInfo();
 
         collectNetworkStats();
@@ -239,16 +242,16 @@ public class MobileRadioPowerStatsCollector extends PowerStatsCollector {
             activityInfo = null;
         }
 
+        if (activityInfo == null) {
+            return;
+        }
+
         ModemActivityInfo deltaInfo = mLastModemActivityInfo == null
-                ? (activityInfo == null ? null : activityInfo.getDelta(activityInfo))
+                ? activityInfo.getDelta(activityInfo)
                 : mLastModemActivityInfo.getDelta(activityInfo);
 
         mLastModemActivityInfo = activityInfo;
 
-        if (deltaInfo == null) {
-            return;
-        }
-
         setTimestamp(deltaInfo.getTimestampMillis());
         mLayout.setDeviceSleepTime(mDeviceStats, deltaInfo.getSleepTimeMillis());
         mLayout.setDeviceIdleTime(mDeviceStats, deltaInfo.getIdleTimeMillis());
@@ -293,8 +296,6 @@ public class MobileRadioPowerStatsCollector extends PowerStatsCollector {
     }
 
     private void collectNetworkStats() {
-        mPowerStats.uidStats.clear();
-
         NetworkStats networkStats = mNetworkStatsSupplier.get();
         if (networkStats == null) {
             return;