[AMBARI-25573] Ambari Metrics save as JSON/CSV use custom fileName instead of default name.

[echohlne]

What changes were proposed in this pull request?

The name of the metrics data exported in Ambari-web is always data.json/csv, and the exported file usually must be renamed to distinguish which metric the data belongs to

so we try to custom the exported metric data file name, make the export function more friendly.

there are some changes in the file name of the exported metrics for example:

Entry	metric name	Old Exported File Name	NewExported Filname
Dashboard	Memory Usage	data.csv/json	memory_usage.csv/json
Services/HDFS	NameNode GC Count	data.csv/json	hdfs_namenode_gc_count.csv/json
Services/HBase	Read Latency	data.csv/json	habse_read_latency.csv.json

How was this patch tested?

checked all the metrics support exported, both shows ok, part of manual test result shows below,

[payert]

@pidhaietsdp Could you take a quick look to this PR? To me it makes sense. Thanks!

[echohlne]

@payert @pidhaietsdp done.

[payert]

LGTM