Replace bash JavaTest.sh with mvn test (#7500)

* Start of mvn-ification of the test

* move to right locations

* Update the IO done in the test to read from resources / write to temp folders

* Add github workflow attempt to mvn test it instead of JavaTest.sh

* Pin the Kotlin benchmark's symlink for /java to the right location

* Inline equality assertions and format JavaTest.java

* fix android gradle source directory

Co-authored-by: Derek Bailey <derekbailey@google.com>

android/app/build.gradle

@@ -21,7 +21,7 @@ android {
     sourceSets {
       main {
         java {
-          srcDir '../../java'
+          srcDir '../../java/src/main/java/'
         }
       }
     }