Hint to UI that scm_credential private_key field should have multiple-line

[jameswnl]

https://bugzilla.redhat.com/show_bug.cgi?id=1451326

Whiling reviewing #14707, it didn't come to my mind that other similar private_key fields need the same change.

Also corrected two field labels.
@miq-bot add_labels bug, blocker, providers/ansible_tower

[miq-bot]

Checked commit jameswnl@f7f5b42 with ruby 2.2.6, rubocop 0.47.1, and haml-lint 0.20.0
1 file checked, 1 offense detected

app/models/manageiq/providers/ansible_tower/shared/automation_manager/scm_credential.rb

• ❗ - Line 25, Col 7 - Style/AlignHash - Align the elements of a hash literal if they span more than one line.

[simaishi]

Fine backport details:

$ git log -1
commit 119e6fddaa7a93dccd51469da25e8beb5d928577
Author: Greg Blomquist <blomquisg@gmail.com>
Date:   Tue May 16 18:22:29 2017 -0400

    Merge pull request #15109 from jameswnl/private_key
    
    Hint to UI that scm_credential private_key field should have multiple-line
    (cherry picked from commit 4e7fe00240fcfe262c05cf2c3cadb77382d37293)
    
    https://bugzilla.redhat.com/show_bug.cgi?id=1451780