Custom Buttons on SupportMapFragment not responding to clicks

Question

I have Android's default "Scrolling Activity". The difference is that I have added a SupportMapFragment to the CollapsingToolbarLayout. Following is the xml:

<android.support.design.widget.AppBarLayout
    android:id="@+id/app_bar"
    android:layout_width="match_parent"
    android:layout_height="@dimen/app_bar_height"
    android:fitsSystemWindows="true"
    android:theme="@style/AppTheme.AppBarOverlay">

    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/toolbar_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true"
        app:contentScrim="?attr/colorPrimary"
        app:layout_scrollFlags="scroll|exitUntilCollapsed"
        app:expandedTitleMarginStart="16dp"
        app:expandedTitleMarginBottom="16dp">

        <fragment xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:app="http://schemas.android.com/apk/res-auto"
            xmlns:tools="http://schemas.android.com/tools"
            android:id="@+id/map"
            android:name="com.google.android.gms.maps.SupportMapFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            tools:context="com.abc.def.ui.activities.tasks.TaskDetailActivity"
            tools:showIn="@layout/activity_task_detail"
            app:layout_collapseMode="parallax">
        </fragment>

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_collapseMode="parallax"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

    </android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>

The map displays fine but when I click the marker, the Map Toolbar Buttons hide behind the FloatingActionButton.

As given here, I tried moving the buttons to other corners but they stopped responding to clicks i.e. I was not redirected to Maps app.

Then I tried extending the SupportMapFragment, added a custom view containing the two buttons to the fragment. And assigned click listeners to button. Again, no response to clicks. Here is the code from the Fragment which extends SupportMapFragment.

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    FrameLayout wrapper = new FrameLayout(inflater.getContext());

    View mapView = super.onCreateView(inflater, container, savedInstanceState);
    wrapper.addView(mapView);

    mCustomView = inflater.inflate(R.layout.toolbar_map, wrapper, false);
    wrapper.addView(mCustomView);

    return wrapper;
}

@Override
public void onActivityCreated(Bundle bundle) {
    super.onActivityCreated(bundle);

    if(mCustomView != null){
        View clickable1 = mCustomView.findViewById(R.id.toolbar_map_btn_1);
        View clickable2 = mCustomView.findViewById(R.id.toolbar_map_btn_2);

        clickable1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(mLatLng != null){
                    Intent intent = new Intent(android.content.Intent.ACTION_VIEW, Uri.parse(
                            "http://maps.google.com/maps?daddr="+mLatLng.latitude+", "+mLatLng.longitude));
                    startActivity(intent);
                }
            }
        });
        clickable2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if(mLatLng != null){
                    Intent intent = new Intent(android.content.Intent.ACTION_VIEW, Uri.parse(
                            "http://maps.google.com/maps?q=loc:"+mLatLng.latitude+", "+mLatLng.longitude));
                    startActivity(intent);
                }
            }
        });
    }
}

Then I tried adding the two buttons to the CollapsingToolbarLayout. This time I referenced the buttons and assigned the click events in the Activity itself. Again, no success.

Every time, I was able to show the buttons on the map, wherever I wanted, but the clicks didn't work, except in the first case when they were partially hidden behind the FAB.

Please help.