Kotlin style fixes (firebase#699)

Author: samtstern

.editorconfig

@@ -0,0 +1,2 @@
+[*.{java,kt}]
+max_line_length = 120

admob/app/src/main/java/com/google/samples/quickstart/admobexample/EntryChoiceActivity.kt

@@ -3,7 +3,6 @@ package com.google.samples.quickstart.admobexample
 import android.content.Intent
 import com.firebase.example.internal.BaseEntryChoiceActivity
 import com.firebase.example.internal.Choice
-import com.google.android.gms.common.util.CollectionUtils.listOf
 import com.google.samples.quickstart.admobexample.java.MainActivity
 
 class EntryChoiceActivity : BaseEntryChoiceActivity() {
@@ -20,5 +19,4 @@ class EntryChoiceActivity : BaseEntryChoiceActivity() {
                         Intent(this, com.google.samples.quickstart.admobexample.kotlin.MainActivity::class.java))
         )
     }
-
 }