Fix lint

Change-Id: Iaecce23ddaada17d67caee1c36fd8060c00d383e

Author: samtstern

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

@@ -47,7 +47,7 @@
                     android:layout_height="wrap_content"
                     android:layout_centerVertical="true"
                     android:padding="8dp"
-                    android:tint="@color/greySecondary"
+                    app:tint="@color/greySecondary"
                     app:srcCompat="@drawable/ic_filter_list_white_24px" />
 
                 <LinearLayout
@@ -87,7 +87,7 @@
                     android:layout_alignParentRight="true"
                     android:layout_centerVertical="true"
                     android:padding="8dp"
-                    android:tint="@color/greySecondary"
+                    app:tint="@color/greySecondary"
                     app:srcCompat="@drawable/ic_close_white_24px" />
 
             </RelativeLayout>

firestore/app/src/main/res/layout/dialog_filters.xml

@@ -23,7 +23,7 @@
             android:id="@+id/icon_category"
             style="@style/AppTheme.FilterIcon"
             android:layout_centerVertical="true"
-            android:tint="@color/greySecondary"
+            app:tint="@color/greySecondary"
             app:srcCompat="@drawable/ic_fastfood_white_24dp" />
 
         <Spinner
@@ -44,7 +44,7 @@
             android:id="@+id/icon_city"
             style="@style/AppTheme.FilterIcon"
             android:layout_centerVertical="true"
-            android:tint="@color/greySecondary"
+            app:tint="@color/greySecondary"
             app:srcCompat="@drawable/ic_place_white_24px" />
 
         <Spinner
@@ -65,7 +65,7 @@
             android:id="@+id/icon_price"
             style="@style/AppTheme.FilterIcon"
             android:layout_centerVertical="true"
-            android:tint="@color/greySecondary"
+            app:tint="@color/greySecondary"
             app:srcCompat="@drawable/ic_monetization_on_white_24px" />
 
         <Spinner
@@ -86,7 +86,7 @@
             android:id="@+id/icon_sort"
             style="@style/AppTheme.FilterIcon"
             android:layout_centerVertical="true"
-            android:tint="@color/greySecondary"
+            app:tint="@color/greySecondary"
             app:srcCompat="@drawable/ic_sort_white_24px" />
 
         <Spinner

firestore/app/src/main/res/values/styles.xml

@@ -21,7 +21,7 @@
 
     <style name="AppTheme.Overflow" parent="Base.Widget.AppCompat.ActionButton.Overflow">
         <item name="android:padding">0dp</item>
-        <item name="android:tint">@android:color/white</item>
+        <item name="tint">@android:color/white</item>
     </style>
 
     <style name="AppTheme.FormLabel">