* [android] fix bug android background color can not be set TRANSPARE…

[atomtong]

• [android] fix bug android background color can not be set TRANSPARENT and this feature is not as same as iOS

[weex-bot]

	Fails
🚫	Running your Dangerfile has Failed

Danger has errored

Error: TypeError

TypeError: Cannot read property 'code' of null
    at Object.<anonymous> (./dangerfile-android.js:101:126)
    at Runtime._execModule (/home/travis/build/apache/incubator-weex/node_modules/jest-runtime/build/index.js:446:13)
    at Runtime.requireModule (/home/travis/build/apache/incubator-weex/node_modules/jest-runtime/build/index.js:294:14)
    at /home/travis/build/apache/incubator-weex/node_modules/danger/distribution/runner/DangerfileRunner.js:136:33
    at ensureCleanDangerfile (/home/travis/build/apache/incubator-weex/node_modules/danger/distribution/runner/DangerfileRunner.js:176:5)
    at Object.<anonymous> (/home/travis/build/apache/incubator-weex/node_modules/danger/distribution/runner/DangerfileRunner.js:135:21)
    at step (/home/travis/build/apache/incubator-weex/node_modules/danger/distribution/runner/DangerfileRunner.js:32:23)
    at Object.next (/home/travis/build/apache/incubator-weex/node_modules/danger/distribution/runner/DangerfileRunner.js:13:53)
    at /home/travis/build/apache/incubator-weex/node_modules/danger/distribution/runner/DangerfileRunner.js:7:71
    at __awaiter (/home/travis/build/apache/incubator-weex/node_modules/danger/distribution/runner/DangerfileRunner.js:3:12)

Generated by 🚫 dangerJS