fix fab shadow issue (#5413) (#5416)

V2rayNG/app/src/main/res/layout/activity_main.xml

@@ -94,6 +94,7 @@
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
                     android:layout_gravity="bottom|end"
+                    android:layout_marginBottom="-16dp"
                     android:layout_marginEnd="@dimen/padding_spacing_dp16">
 
                     <com.google.android.material.floatingactionbutton.FloatingActionButton
@@ -106,6 +107,7 @@
                         android:contentDescription="@string/title_server"
                         android:focusable="true"
                         android:src="@android:drawable/ic_menu_mylocation"
+                        app:useCompatPadding="true"
                         app:layout_anchorGravity="bottom|right|end" />
 
                     <com.google.android.material.floatingactionbutton.FloatingActionButton
@@ -120,6 +122,7 @@
                         android:nextFocusLeft="@+id/layout_test"
                         android:src="@drawable/ic_play_24dp"
                         app:tint="@color/colorWhite"
+                        app:useCompatPadding="true"
                         app:layout_anchorGravity="bottom|right|end" />
 
                 </FrameLayout>