Use desugaring to upgrade zxing without having to increase minSdk

As documented by the zxing team on https://github.com/zxing/zxing/wiki/Frequently-Asked-Questions#it-doesnt-work-with-java-7--no-interface-method-sortljavautilcomparator

app/build.gradle

@@ -22,6 +22,7 @@ android {
         versionName "2.0.4"
 
         vectorDrawables.useSupportLibrary true
+        multiDexEnabled true
     }
 
     buildTypes {
@@ -38,6 +39,10 @@ android {
 
     compileOptions {
         encoding "UTF-8"
+
+        // Flag to enable support for the new language APIs
+        coreLibraryDesugaringEnabled true
+
         sourceCompatibility JavaVersion.VERSION_1_8
         targetCompatibility JavaVersion.VERSION_1_8
     }
@@ -74,12 +79,11 @@ dependencies {
     implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
     implementation 'androidx.preference:preference:1.1.1'
     implementation 'com.google.android.material:material:1.4.0'
+    coreLibraryDesugaring 'com.android.tools:desugar_jdk_libs:1.1.5'
 
 // Third-party
     implementation 'com.journeyapps:zxing-android-embedded:4.1.0@aar'
-    // Do not upgrade past 3.3.3! Causes a crash on versions before Android Nougat
-    //noinspection GradleDependency
-    implementation 'com.google.zxing:core:3.3.3'
+    implementation 'com.google.zxing:core:3.4.1'
     implementation 'org.apache.commons:commons-csv:1.8'
     implementation 'com.jaredrummler:colorpicker:1.1.0'
     implementation 'com.google.guava:guava:30.1.1-jre'

app/src/main/java/protect/card_locker/LoyaltyCardLockerApplication.java

@@ -1,11 +1,10 @@
 package protect.card_locker;
 
-import android.app.Application;
-
 import androidx.appcompat.app.AppCompatDelegate;
+import androidx.multidex.MultiDexApplication;
 import protect.card_locker.preferences.Settings;
 
-public class LoyaltyCardLockerApplication extends Application {
+public class LoyaltyCardLockerApplication extends MultiDexApplication {
     public void onCreate() {
         super.onCreate();