Fix NPE crash on startup when storage manager is not set

Fixes #4941

Signed-off-by: Chris Narkiewicz <hello@ezaquarii.com>

src/main/java/com/owncloud/android/ui/activity/BaseActivity.java

@@ -69,6 +69,13 @@ public abstract class BaseActivity extends AppCompatActivity implements Injectab
         return accountManager;
     }
 
+    @Override
+    protected void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        Account account = accountManager.getCurrentAccount();
+        setAccount(account, false);
+    }
+
     @Override
     protected void onPostCreate(@Nullable Bundle savedInstanceState) {
         super.onPostCreate(savedInstanceState);
@@ -97,12 +104,6 @@ public abstract class BaseActivity extends AppCompatActivity implements Injectab
         }
     }
 
-    public void onCreate(@Nullable Bundle savedInstanceState, @Nullable PersistableBundle persistentState) {
-        super.onCreate(savedInstanceState, persistentState);
-        Account account = accountManager.getCurrentAccount();
-        setAccount(account, false);
-    }
-
     @Override
     protected void onNewIntent(Intent intent) {
         super.onNewIntent(intent);
@@ -177,6 +178,7 @@ public abstract class BaseActivity extends AppCompatActivity implements Injectab
         if (newAccount == null) {
             /// no account available: force account creation
             createAccount(true);
+            finish();
         } else {
             currentAccount = newAccount;
         }

src/main/java/com/owncloud/android/ui/activity/FileDisplayActivity.java

@@ -2539,8 +2539,9 @@ public class FileDisplayActivity extends FileActivity
     @Override
     public void onStart() {
         super.onStart();
-        Optional<User> optionalUser = getUser();
-        if (optionalUser.isPresent()) {
+        final Optional<User> optionalUser = getUser();
+        final FileDataStorageManager storageManager = getStorageManager();
+        if (optionalUser.isPresent() && storageManager != null) {
             /// Check whether the 'main' OCFile handled by the Activity is contained in the
             // current Account
             OCFile file = getFile();
@@ -2552,17 +2553,17 @@ public class FileDisplayActivity extends FileActivity
                     // cache until the upload is successful get parent from path
                     parentPath = file.getRemotePath().substring(0,
                                                                 file.getRemotePath().lastIndexOf(file.getFileName()));
-                    if (getStorageManager().getFileByPath(parentPath) == null) {
+                    if (storageManager.getFileByPath(parentPath) == null) {
                         file = null; // not able to know the directory where the file is uploading
                     }
                 } else {
-                    file = getStorageManager().getFileByPath(file.getRemotePath());
+                    file = storageManager.getFileByPath(file.getRemotePath());
                     // currentDir = null if not in the current Account
                 }
             }
             if (file == null) {
                 // fall back to root folder
-                file = getStorageManager().getFileByPath(OCFile.ROOT_PATH);  // never returns null
+                file = storageManager.getFileByPath(OCFile.ROOT_PATH);  // never returns null
             }
             setFile(file);