fix: call lifecycle addObserver on main thread (#347)

* addObserver crash fix

* addObserver crash fix

Co-authored-by: Chaitanya Anand <canand@mphrx.com>

Author: chaits98

android/src/main/java/com/reactcommunity/rndatetimepicker/RNDatePickerDialogModule.java

@@ -117,16 +117,16 @@ public void dismiss(Promise promise) {
    *                dismiss, year, month and date are undefined.
    */
   @ReactMethod
-  public void open(@Nullable final ReadableMap options, Promise promise) {
+  public void open(@Nullable final ReadableMap options, final Promise promise) {
     FragmentActivity activity = (FragmentActivity) getCurrentActivity();
     if (activity == null) {
       promise.reject(
-          RNConstants.ERROR_NO_ACTIVITY,
-          "Tried to open a DatePicker dialog while not attached to an Activity");
+        RNConstants.ERROR_NO_ACTIVITY,
+        "Tried to open a DatePicker dialog while not attached to an Activity");
       return;
     }
 
-    FragmentManager fragmentManager = activity.getSupportFragmentManager();
+    final FragmentManager fragmentManager = activity.getSupportFragmentManager();
     final RNDatePickerDialogFragment oldFragment = (RNDatePickerDialogFragment) fragmentManager.findFragmentByTag(FRAGMENT_TAG);
 
     if (oldFragment != null && options != null) {
@@ -140,17 +140,22 @@ public void run() {
       return;
     }
 
-    RNDatePickerDialogFragment fragment = new RNDatePickerDialogFragment();
+    UiThreadUtil.runOnUiThread(new Runnable() {
+      @Override
+      public void run() {
+        RNDatePickerDialogFragment fragment = new RNDatePickerDialogFragment();
 
-    if (options != null) {
-      fragment.setArguments(createFragmentArguments(options));
-    }
+        if (options != null) {
+          fragment.setArguments(createFragmentArguments(options));
+        }
 
-    final DatePickerDialogListener listener = new DatePickerDialogListener(promise);
-    fragment.setOnDismissListener(listener);
-    fragment.setOnDateSetListener(listener);
-    fragment.setOnNeutralButtonActionListener(listener);
-    fragment.show(fragmentManager, FRAGMENT_TAG);
+        final DatePickerDialogListener listener = new DatePickerDialogListener(promise);
+        fragment.setOnDismissListener(listener);
+        fragment.setOnDateSetListener(listener);
+        fragment.setOnNeutralButtonActionListener(listener);
+        fragment.show(fragmentManager, FRAGMENT_TAG);
+      }
+    });
   }
 
   private Bundle createFragmentArguments(ReadableMap options) {

android/src/main/java/com/reactcommunity/rndatetimepicker/RNTimePickerDialogModule.java

@@ -92,7 +92,7 @@ public void dismiss(Promise promise) {
   }
 
   @ReactMethod
-  public void open(@Nullable final ReadableMap options, Promise promise) {
+  public void open(@Nullable final ReadableMap options, final Promise promise) {
 
     FragmentActivity activity = (FragmentActivity) getCurrentActivity();
     if (activity == null) {
@@ -103,7 +103,7 @@ public void open(@Nullable final ReadableMap options, Promise promise) {
     }
     // We want to support both android.app.Activity and the pre-Honeycomb FragmentActivity
     // (for apps that use it for legacy reasons). This unfortunately leads to some code duplication.
-    FragmentManager fragmentManager = activity.getSupportFragmentManager();
+    final FragmentManager fragmentManager = activity.getSupportFragmentManager();
     final RNTimePickerDialogFragment oldFragment = (RNTimePickerDialogFragment) fragmentManager.findFragmentByTag(FRAGMENT_TAG);
 
     if (oldFragment != null && options != null) {
@@ -117,17 +117,22 @@ public void run() {
       return;
     }
 
-    RNTimePickerDialogFragment fragment = new RNTimePickerDialogFragment();
+    UiThreadUtil.runOnUiThread(new Runnable() {
+      @Override
+      public void run() {
+        RNTimePickerDialogFragment fragment = new RNTimePickerDialogFragment();
 
-    if (options != null) {
-      fragment.setArguments(createFragmentArguments(options));
-    }
+        if (options != null) {
+          fragment.setArguments(createFragmentArguments(options));
+        }
 
-    final TimePickerDialogListener listener = new TimePickerDialogListener(promise);
-    fragment.setOnDismissListener(listener);
-    fragment.setOnTimeSetListener(listener);
-    fragment.setOnNeutralButtonActionListener(listener);
-    fragment.show(fragmentManager, FRAGMENT_TAG);
+        final TimePickerDialogListener listener = new TimePickerDialogListener(promise);
+        fragment.setOnDismissListener(listener);
+        fragment.setOnTimeSetListener(listener);
+        fragment.setOnNeutralButtonActionListener(listener);
+        fragment.show(fragmentManager, FRAGMENT_TAG);
+      }
+    });
   }
 
   private Bundle createFragmentArguments(ReadableMap options) {