Remove Multidex usages

Since the min SDK is 21, it is no longer necessary to use the Multidex library.

See the following for more info: developer.android.com/build/multidex#mdex-on-l

README.md

@@ -40,7 +40,6 @@ git clone https://github.com/dimagi/commcare-core.git
 - Click "OK" to use the Gradle wrapper
 - Wait while Android Studio spins its wheels
 - Download any build dependencies that the SDK Manager tells you you need.
-- Disable _Instant Run_ found in Settings > Build, Execution, Deployment > Instant Run. (It does not play well with multidexing, which we have enabled, or with some of the processes we have set up for Google Services)
 
 ## Building
 

app/build.gradle

@@ -34,7 +34,6 @@ dependencies {
     testImplementation('org.robolectric:robolectric:4.8.2') {
         exclude(group: 'org.bouncycastle', module: 'bcprov-jdk15on')
     }
-    testImplementation 'org.robolectric:shadows-multidex:4.8.2'
     testImplementation 'androidx.test:core:1.5.0'
     testImplementation 'androidx.test:runner:1.5.2'
     testImplementation 'androidx.test.ext:junit:1.1.3'
@@ -75,7 +74,6 @@ dependencies {
     implementation (name: 'volley-1.1.0', ext: 'aar')
     implementation (name: 'storage-2.1.0', ext: 'aar')
     implementation 'androidx.appcompat:appcompat:1.2.0'
-    implementation 'androidx.multidex:multidex:2.0.1'
     implementation 'androidx.cardview:cardview:1.0.0'
     implementation 'androidx.recyclerview:recyclerview:1.1.0'
     implementation 'androidx.legacy:legacy-support-v4:1.0.0'
@@ -251,7 +249,6 @@ android {
     defaultConfig {
         minSdkVersion 21
         targetSdkVersion 33
-        multiDexEnabled true
         applicationId 'org.commcare.dalvik'
         testNamespace 'org.commcare.dalvik.test'
 
@@ -462,7 +459,6 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard.cfg'
             testProguardFiles 'test-proguard.cfg'
 
-            multiDexKeepProguard file('proguard-multidex.pro')
             // enable crashlytics
             buildConfigField 'boolean', 'USE_CRASHLYTICS', 'true'
             ext.enableCrashlytics = true

app/src/org/commcare/CommCareApplication.java

@@ -2,6 +2,7 @@
 
 import android.annotation.SuppressLint;
 import android.app.ActivityManager;
+import android.app.Application;
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
@@ -17,7 +18,6 @@
 import android.util.Log;
 
 import androidx.annotation.NonNull;
-import androidx.multidex.MultiDexApplication;
 import androidx.preference.PreferenceManager;
 import androidx.work.BackoffPolicy;
 import androidx.work.Constraints;
@@ -143,7 +143,7 @@
 import okhttp3.MultipartBody;
 import okhttp3.RequestBody;
 
-public class CommCareApplication extends MultiDexApplication {
+public class CommCareApplication extends Application {
 
     private static final String TAG = CommCareApplication.class.getSimpleName();