android: Remove AndroidX legacy support

src/frontends/android/app/build.gradle

@@ -46,7 +46,6 @@ android {
 dependencies {
     implementation 'androidx.appcompat:appcompat:1.6.1'
     implementation 'androidx.preference:preference:1.2.1'
-    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
     implementation 'com.google.android.material:material:1.10.0'
     testImplementation 'junit:junit:4.13.2'
     testImplementation 'org.mockito:mockito-core:5.8.0'