refactor(build): support multiple configurable browsers for e2e and perf tests

Also includes browser configuration for Android

scripts/ci/test_unit.sh

@@ -0,0 +1,15 @@
+#!/bin/bash
+set -e
+
+echo =============================================================================
+# go to project dir
+SCRIPT_DIR=$(dirname $0)
+source $SCRIPT_DIR/env_dart.sh
+cd $SCRIPT_DIR/../..
+
+./node_modules/karma/bin/karma start karma-js.conf \
+        --reporters=dots \
+        --browsers=$KARMA_BROWSERS --single-run
+./node_modules/karma/bin/karma start karma-dart.conf \
+        --reporters=dots \
+        --browsers=$KARMA_BROWSERS --single-run