Let the app be compatible with android 16

app/build.gradle

@@ -15,8 +15,9 @@ android {
     compileSdkVersion 28
     defaultConfig {
         applicationId "im.vector.riotredesign"
-        minSdkVersion 21
+        minSdkVersion 16
         targetSdkVersion 28
+        multiDexEnabled true
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -42,6 +43,7 @@ dependencies {
 
     implementation project(":matrix-sdk-android")
     implementation project(":matrix-sdk-android-rx")
+    implementation 'com.android.support:multidex:1.0.3'
 
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
 

app/src/main/java/im/vector/riotredesign/Riot.kt

@@ -1,6 +1,8 @@
 package im.vector.riotredesign
 
 import android.app.Application
+import android.content.Context
+import androidx.multidex.MultiDex
 import com.jakewharton.threetenabp.AndroidThreeTen
 import im.vector.matrix.android.BuildConfig
 import im.vector.riotredesign.core.di.AppModule
@@ -8,6 +10,7 @@ import org.koin.log.EmptyLogger
 import org.koin.standalone.StandAloneContext.startKoin
 import timber.log.Timber
 
+
 class Riot : Application() {
 
     override fun onCreate() {
@@ -19,4 +22,9 @@ class Riot : Application() {
         startKoin(listOf(AppModule(this).definition), logger = EmptyLogger())
     }
 
+    override fun attachBaseContext(base: Context) {
+        super.attachBaseContext(base)
+        MultiDex.install(this)
+    }
+
 }

app/src/main/java/im/vector/riotredesign/features/home/room/list/RoomCategoryItem.kt

@@ -1,8 +1,9 @@
 package im.vector.riotredesign.features.home.room.list
 
-import androidx.core.content.ContextCompat
 import android.view.ViewGroup
 import android.widget.TextView
+import androidx.core.content.ContextCompat
+import androidx.core.graphics.drawable.DrawableCompat
 import im.vector.riotredesign.R
 import im.vector.riotredesign.core.epoxy.KotlinModel
 
@@ -21,8 +22,9 @@ data class RoomCategoryItem(
 
     override fun bind() {
         val expandedArrowDrawableRes = if (isExpanded) R.drawable.ic_expand_more_white else R.drawable.ic_expand_less_white
-        val expandedArrowDrawable = ContextCompat.getDrawable(rootView.context, expandedArrowDrawableRes)
-        expandedArrowDrawable?.setTint(tintColor)
+        val expandedArrowDrawable = ContextCompat.getDrawable(rootView.context, expandedArrowDrawableRes)?.also {
+            DrawableCompat.setTint(it, tintColor)
+        }
         titleView.setCompoundDrawablesWithIntrinsicBounds(expandedArrowDrawable, null, null, null)
         titleView.text = title
         rootView.setOnClickListener { listener?.invoke() }

matrix-sdk-android/build.gradle

@@ -24,7 +24,7 @@ android {
     testOptions.unitTests.includeAndroidResources = true
 
     defaultConfig {
-        minSdkVersion 21
+        minSdkVersion 16
         targetSdkVersion 28
         versionCode 1
         versionName "1.0"