fix/add tests, update heatmap range, finish android release, add readme

Stop tracking gradle.properties

client/android/build.gradle

@@ -1,5 +1,3 @@
-// Top-level build file where you can add configuration options common to all sub-projects/modules.
-
 buildscript {
     
     repositories {
@@ -9,9 +7,6 @@ buildscript {
     dependencies {
         classpath 'com.android.tools.build:gradle:8.7.2'
         classpath 'com.google.gms:google-services:4.4.2'
-
-        // NOTE: Do not place your application dependencies here; they belong
-        // in the individual module build.gradle files
     }
 }