android floating window (#8268)

Signed-off-by: 21pages <sunboeasy@gmail.com>

flutter/android/app/build.gradle

@@ -106,5 +106,6 @@ dependencies {
     implementation "androidx.media:media:1.6.0"
     implementation 'com.github.getActivity:XXPermissions:18.5'
     implementation("org.jetbrains.kotlin:kotlin-stdlib") { version { strictly("$kotlin_version") } }
+    implementation 'com.caverock:androidsvg-aar:1.4'
 }