Fix some build warnings

app/src/googleplay/java/org/tasks/analytics/Firebase.kt

@@ -69,7 +69,7 @@ class Firebase @Inject constructor(@ForApplication val context: Context, prefere
 
     init {
         if (enabled) {
-            analytics = FirebaseAnalytics.getInstance(context!!)
+            analytics = FirebaseAnalytics.getInstance(context)
             analytics?.setAnalyticsCollectionEnabled(true)
             Fabric.with(context, Crashlytics())
             remoteConfig = FirebaseRemoteConfig.getInstance()

app/src/main/java/org/tasks/data/TaskAttachment.kt

@@ -47,7 +47,7 @@ class TaskAttachment {
     }
 
     fun convertPathUri() {
-        setUri(Uri.fromFile(File(uri)).toString())
+        setUri(Uri.fromFile(File(uri!!)).toString())
     }
 
     fun parseUri(): Uri? {

app/src/main/res/values/keys.xml

@@ -348,7 +348,7 @@
   <string name="subscription_help_url">https://tasks.org/subscribe</string>
   <string name="p_disable_subtasks">disable_subtasks</string>
   <string name="p_wearable_notifications">wearable_notifications</string>
-  <string name="p_notified_oauth_error">notified_oauth_error_%s_%s</string>
+  <string name="p_notified_oauth_error">notified_oauth_error_%1$s_%2$s</string>
   <string name="p_chip_style">chip_style</string>
   <string name="p_chip_appearance">chip_appearance</string>
   <string name="p_desaturate_colors">desaturate_colors</string>