Bug 1838717 - Enable alerting for APK file size. (#2505)

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

buildSrc/src/main/java/org/mozilla/fenix/gradle/tasks/ApkSizeTask.kt

@@ -102,7 +102,8 @@ open class ApkSizeTask : DefaultTask() {
             suite.put("name", "apk-size-$variantName")
             suite.put("value", getSummarySize(apkSize))
             suite.put("lowerIsBetter", true)
-            suite.put("shouldAlert", false)
+            suite.put("alertChangeType", "absolute")
+            suite.put("alertThreshold", 100 * 1024)
 
             val subtests = JSONArray()
             apkSize.forEach { (apk, size) ->