add AndroidSocialBackupModule to AppModule

briar-android/src/main/java/org/briarproject/briar/android/AppModule.java

@@ -48,6 +48,7 @@ import org.briarproject.briar.api.android.DozeWatchdog;
 import org.briarproject.briar.api.android.LockManager;
 import org.briarproject.briar.api.android.ScreenFilterMonitor;
 import org.briarproject.briar.api.test.TestAvatarCreator;
+import org.briarproject.briar.socialbackup.AndroidSocialBackupModule;
 
 import java.io.File;
 import java.security.GeneralSecurityException;
@@ -82,6 +83,7 @@ import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 		SettingsModule.class,
 		DevReportModule.class,
 		ContactListModule.class,
+		AndroidSocialBackupModule.class,
 		// below need to be within same scope as ViewModelProvider.Factory
 		ForumModule.class,
 		GroupListModule.class,

briar-android/src/main/java/org/briarproject/briar/android/socialbackup/DarkCrystalImpl.java

@@ -1,5 +1,6 @@
 package org.briarproject.briar.android.socialbackup;
 import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.api.socialbackup.Shard;
 import org.briarproject.briar.api.socialbackup.DarkCrystal;
 import org.magmacollective.darkcrystal.secretsharingwrapper.SecretSharingWrapper;
@@ -10,10 +11,19 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Random;
 
+import javax.inject.Inject;
+
+import dagger.Provides;
+
 import static org.briarproject.briar.socialbackup.SocialBackupConstants.SECRET_ID_BYTES;
 
+@NotNullByDefault
 public class DarkCrystalImpl implements DarkCrystal {
 
+    @Inject
+	DarkCrystalImpl() {
+	}
+
 	@Override
 	public List<Shard> createShards(SecretKey secret, int numShards,
 			int threshold) {

briar-core/src/main/java/org/briarproject/briar/socialbackup/DefaultSocialBackupModule.java

@@ -21,7 +21,7 @@ import static org.briarproject.briar.api.socialbackup.SocialBackupManager.MAJOR_
 import static org.briarproject.briar.api.socialbackup.SocialBackupManager.MINOR_VERSION;
 
 @Module
-public class SocialBackupModule {
+public class DefaultSocialBackupModule {
 
 	public static class EagerSingletons {
 		@Inject