Fixed some issues with pushing in tabs

android/app/src/main/java/com/reactnativenavigation/activities/BottomTabActivity.java

     @Override
     public Screen pop(String navigatorId) {
         super.pop(navigatorId);
-        Screen screen = mScreenStacks.get(mCurrentStackPosition).pop();
-        Screen currentScreen = getCurrentScreen();
-        setNavigationStyle(currentScreen);
-        mToolbar.update(currentScreen);
-        return screen;
+        for (ScreenStack stack: mScreenStacks) {
+            if (stack.peek().navigatorId.equals(navigatorId)) {
+                Screen popped = stack.pop();
+                setNavigationStyle(getCurrentScreen());
+                return popped;
+            }
+        }
+        return null;
     }
 
     @Override

android/app/src/main/java/com/reactnativenavigation/modal/RnnModal.java

     }
 
     public Screen pop() {
+        Screen popped = mScreenStack.pop();
         if (mScreenStack.isEmpty()) {
             ModalController.getInstance().remove();
-            super.onBackPressed();
-            return null;
-        } else {
-            return mScreenStack.pop();
+            dismiss();
         }
+        return popped;
     }
 
     @Override

android/app/src/main/java/com/reactnativenavigation/modules/RctActivityModule.java

                 });
             }
             return;
+        } else {
+            context.runOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    context.pop(navigatorId);
+                }
+            });
         }
 
-        context.runOnUiThread(new Runnable() {
-            @Override
-            public void run() {
-                context.pop(navigatorId);
-            }
-        });
     }
 
     @ReactMethod