Add multidex to UI tests

gradle/libs.versions.toml

diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 608a508..43265b8 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -41,6 +41,7 @@
 # and they'll automatically resolve to higher version without having to necessarily resort to a
 # resolution strategy.
 androidX-fragment = { module = "androidx.fragment:fragment", version = "1.0.0" }
+androidX-multidex = { module = "androidx.multidex:multidex", version = "2.0.1" }
 # Exposed transitively, avoid increasing
 androidX-startup = { module = "androidx.startup:startup-runtime", version = "1.0.0" }
 androidX-test-core = { module = "androidx.test:core", version = "1.4.0" }

leakcanary/leakcanary-android-instrumentation/build.gradle

diff --git a/leakcanary/leakcanary-android-instrumentation/build.gradle b/leakcanary/leakcanary-android-instrumentation/build.gradle
index 16c7a58..5bbf189 100644
--- a/leakcanary/leakcanary-android-instrumentation/build.gradle
+++ b/leakcanary/leakcanary-android-instrumentation/build.gradle
@@ -15,6 +15,7 @@
   androidTestImplementation projects.objectWatcher.objectWatcherAndroid
   // Plumber auto installer for running tests
   androidTestImplementation projects.plumber.plumberAndroid
+  androidTestImplementation libs.androidX.multidex
   androidTestImplementation libs.androidX.test.core
   androidTestImplementation libs.androidX.test.espresso
   androidTestImplementation libs.androidX.test.rules
@@ -28,6 +29,7 @@
     targetSdk versions.compileSdk
     minSdk versions.minSdk
     testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    multiDexEnabled true
   }
   buildFeatures.buildConfig = false
   namespace 'com.squareup.leakcanary.instrumentation'

leakcanary/leakcanary-android-instrumentation/src/androidTest/AndroidManifest.xml

diff --git a/leakcanary/leakcanary-android-instrumentation/src/androidTest/AndroidManifest.xml b/leakcanary/leakcanary-android-instrumentation/src/androidTest/AndroidManifest.xml
index 2743ca7..700c2fc 100644
--- a/leakcanary/leakcanary-android-instrumentation/src/androidTest/AndroidManifest.xml
+++ b/leakcanary/leakcanary-android-instrumentation/src/androidTest/AndroidManifest.xml
@@ -16,7 +16,9 @@
   -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
-  <application>
+  <application
+    android:name="androidx.multidex.MultiDexApplication"
+    >
     <activity android:name="leakcanary.TestActivity"/>
   </application>
 </manifest>