Segment metadata queries fail on string columns with disabled bitmaps

[Caroline1000]

Bug Report

Segment metadata queries return an error on a string column with bitmaps disabled:
"errorMessage": "error:string_no_bitmap"

Recent support for disabling bitmaps (#5402) didn't include modification to incubator-druid/processing/src/main/java/org/apache/druid/query/metadata/SegmentAnalyzer.java.

analyzeStringColumn in SegmentAnalyzer.java should be modified to allow disabled bitmaps:

https://github.com/apache/incubator-druid/blob/676f5e6d7f184101b8763e4249b18b237bbe0ec7/processing/src/main/java/org/apache/druid/query/metadata/SegmentAnalyzer.java#L202