only disable lint in the basic flavor for UnusedResources

My hack before was actually always making exit with success, breaking the
CI runs :-/  I loathe gradle and groovy with a passion.

app/build.gradle

@@ -179,12 +179,6 @@ dependencies {
     androidTestImplementation 'com.android.support.test:rules:1.0.2'
 }
 
-tasks.whenTaskAdded { task ->
-    if (task.name.startsWith("lintBasic")) {
-        android.lintOptions.abortOnError = false
-    }
-}
-
 checkstyle {
     toolVersion = '7.2'
 }

app/lint.xml

@@ -15,6 +15,8 @@
         <ignore path="src/main/res/drawable/category_**.png" />
         <ignore path="src/main/res/values/dimens.xml"/>
         <ignore path="src/main/res/values/styles.xml"/>
+        <!-- keep a single strings.xml for all build flavors -->
+        <ignore path="src/main/res/values**/strings.xml"/>
     </issue>
     <issue id="AppCompatMethod" severity="error"/>
     <issue id="NestedScrolling" severity="error"/>