Prevent narrow race condition when resetting network components.

app/src/main/java/org/thoughtcrime/securesms/dependencies/ApplicationDependencies.java

@@ -95,16 +95,19 @@ public class ApplicationDependencies {
   }
 
   public static @NonNull SignalServiceAccountManager getSignalServiceAccountManager() {
-    if (accountManager == null) {
+    SignalServiceAccountManager local = accountManager;
+
+    if (local != null) {
+      return local;
+    }
+
     synchronized (LOCK) {
       if (accountManager == null) {
         accountManager = provider.provideSignalServiceAccountManager();
       }
-      }
-    }
-
       return accountManager;
     }
+  }
 
   public static @NonNull GroupsV2Authorization getGroupsV2Authorization() {
     if (groupsV2Authorization == null) {
@@ -152,6 +155,12 @@ public class ApplicationDependencies {
   }
 
   public static @NonNull SignalServiceMessageSender getSignalServiceMessageSender() {
+    SignalServiceMessageSender local = messageSender;
+
+    if (local != null) {
+      return local;
+    }
+
     synchronized (LOCK) {
       if (messageSender == null) {
         messageSender = provider.provideSignalServiceMessageSender();
@@ -161,22 +170,24 @@ public class ApplicationDependencies {
             IncomingMessageObserver.getUnidentifiedPipe(),
             TextSecurePreferences.isMultiDevice(application));
       }
-    }
-
       return messageSender;
     }
+  }
 
   public static @NonNull SignalServiceMessageReceiver getSignalServiceMessageReceiver() {
-    if (messageReceiver == null) {
+    SignalServiceMessageReceiver local = messageReceiver;
+
+    if (local != null) {
+      return local;
+    }
+
     synchronized (LOCK) {
       if (messageReceiver == null) {
         messageReceiver = provider.provideSignalServiceMessageReceiver();
       }
-      }
-    }
-
       return messageReceiver;
     }
+  }
 
   public static void resetSignalServiceMessageReceiver() {
     synchronized (LOCK) {
@@ -301,16 +312,19 @@ public class ApplicationDependencies {
   }
 
   public static @NonNull IncomingMessageObserver getIncomingMessageObserver() {
-    if (incomingMessageObserver == null) {
+    IncomingMessageObserver local = incomingMessageObserver;
+
+    if (local != null) {
+      return local;
+    }
+
     synchronized (LOCK) {
       if (incomingMessageObserver == null) {
         incomingMessageObserver = provider.provideIncomingMessageObserver();
       }
-      }
-    }
-
       return incomingMessageObserver;
     }
+  }
 
   public static @NonNull TrimThreadsByDateManager getTrimThreadsByDateManager() {
     if (trimThreadsByDateManager == null) {