[Java] Change vector getMinorType to use MinorType instead of Types.MinorType

[asfimport]

This is just some renaming to clean things up.

Reporter: Bryan Cutler / @BryanCutler
Assignee: Bryan Cutler / @BryanCutler

PRs and other links:

• GitHub Pull Request #1831
• GitHub Pull Request #1831

_{Note: This issue was originally created as ARROW-1868. Please see the migration documentation for further details.}

[asfimport]

Bryan Cutler / @BryanCutler:
Is this still something we want to be in 0.8? @siddharthteotia @icexelloss

[asfimport]

Li Jin / @icexelloss:
I don't think this has to be in 0.8 - more of a clean up. I am ok with leaving it out.

[asfimport]

Wes McKinney / @wesm:
Is this an API change?

[asfimport]

Li Jin / @icexelloss:
It's not an API change.