Whitelist lint warning for missing tools:targetApi attr. (#728)

* Whitelist lint warning for missing tools:targetApi attr.

* Add TODO to remove the warning from the whitelist.

Author: rlazo

firebase-common/firebase-common.gradle

@@ -55,6 +55,9 @@ android {
             includeAndroidResources = true
         }
     }
+    lintOptions {
+        baseline file("lint-baseline.xml")
+    }
 }
 
 dependencies {

firebase-common/lint-baseline.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="5" by="lint 3.4.1" client="gradle" variant="all" version="3.4.1">
+  <!-- TODO: remove when bazel support tools:targetApi -->
+    <issue
+        id="UnusedAttribute"
+        message="Attribute `directBootAware` is only used in API level 24 and higher (current min is 14)"
+        errorLine1="        android:directBootAware=&quot;true&quot; android:exported=&quot;false&quot;/>"
+        errorLine2="        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~">
+        <location
+            file="src/main/AndroidManifest.xml"
+            line="11"
+            column="9"/>
+    </issue>
+
+</issues>

firebase-common/src/main/AndroidManifest.xml

@@ -8,8 +8,7 @@
   <application>
 
     <service android:name="com.google.firebase.components.ComponentDiscoveryService"
-        android:directBootAware="true" android:exported="false"
-        tools:targetApi="n" />
+        android:directBootAware="true" android:exported="false"/>
 
     <provider
         android:name="com.google.firebase.provider.FirebaseInitProvider"