optimize prefetch dns

[YangSen-qn]

1. 优化 DNS 缓存使用策略，增加缓存最大有效时间
2. uc host 默认不添加至预取队列
3. 网络检测可关闭
4. 统计上传速度

[YangSen-qn]

done

[codecov]

Codecov Report

Merging #465 (239a52a) into master (59bee19) will decrease coverage by 0.32%.
The diff coverage is 70.35%.

@@             Coverage Diff              @@
##             master     #465      +/-   ##
============================================
- Coverage     70.28%   69.96%   -0.33%     
- Complexity     1163     1189      +26     
============================================
  Files            93       95       +2     
  Lines          6149     6233      +84     
  Branches        920      936      +16     
============================================
+ Hits           4322     4361      +39     
- Misses         1199     1222      +23     
- Partials        628      650      +22     

Impacted Files	Coverage Δ
...ain/java/com/qiniu/android/collect/ReportItem.java	77.27% <ø> (ø)
.../main/java/com/qiniu/android/common/Constants.java	0.00% <ø> (ø)
.../qiniu/android/http/metrics/UploadTaskMetrics.java	83.33% <ø> (-0.39%)	⬇️
...iniu/android/http/request/httpclient/ByteBody.java	100.00% <ø> (ø)
.../java/com/qiniu/android/storage/Configuration.java	90.47% <ø> (ø)
...droid/http/metrics/UploadRegionRequestMetrics.java	61.76% <25.00%> (-9.29%)	⬇️
.../com/qiniu/android/http/dns/DnsNetworkAddress.java	55.10% <37.50%> (-3.44%)	⬇️
.../main/java/com/qiniu/android/http/dns/HttpDns.java	46.66% <46.66%> (ø)
...c/main/java/com/qiniu/android/common/AutoZone.java	75.58% <50.00%> (-1.25%)	⬇️
.../qiniu/android/http/request/HttpSingleRequest.java	78.26% <55.55%> (-5.84%)	⬇️
... and 25 more