Add missing kotlin-coroutines-android dependency (#1939)

The files module needs Dispatchers.Main

dependencies.gradle

@@ -31,7 +31,7 @@ ext.deps = [
     kotlin: [
         stdlib8: "org.jetbrains.kotlin:kotlin-stdlib-jdk8",
         coroutines: [
-            core: "org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.2"
+            android: "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.2"
         ]
     ],
 

files/build.gradle

@@ -7,6 +7,6 @@ dependencies {
   api project(':core')
   api project(':input')
 
-  implementation deps.kotlin.coroutines.core
+  implementation deps.kotlin.coroutines.android
   implementation deps.kotlin.stdlib8
 }