Don't crash when low storage is encountered pre-boot completion.

Bug: 2741633
Change-Id: Ic073ead64ff43b2e2c32b439756cd71c2b6550b8
diff --git a/services/java/com/android/server/DeviceStorageMonitorService.java b/services/java/com/android/server/DeviceStorageMonitorService.java
index 62cf7076..4a0df59 100644
--- a/services/java/com/android/server/DeviceStorageMonitorService.java
+++ b/services/java/com/android/server/DeviceStorageMonitorService.java
@@ -280,7 +280,9 @@
         mTotalMemory = ((long)mDataFileStats.getBlockCount() *
                         mDataFileStats.getBlockSize())/100L;
         mStorageLowIntent = new Intent(Intent.ACTION_DEVICE_STORAGE_LOW);
+        mStorageLowIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
         mStorageOkIntent = new Intent(Intent.ACTION_DEVICE_STORAGE_OK);
+        mStorageOkIntent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
         checkMemory(true);
     }