Cleaner vector/array initializations

[moprak-nrel]

Summary

Cleaner/consistent initialization of vectors and arrays, amrex::Vector<amrex::Real> foo {0.0,0.0} is a lot cleaner than amrex::Vector<amrex::Real> foo{{0.0,0.0}}.

Pull request type

Please check the type of change introduced:

• [ ] Bugfix
• [ ] Feature
• [x] Code style update (formatting, renaming)
• [ ] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] Documentation content changes
• [ ] Other (please describe):

Checklist

The following is included:

• [ ] new unit-test(s)
• [ ] new regression test(s)
• [ ] documentation for new capability

This PR was tested by running:

• the unit tests
  • [x] on GPU
  • [x] on CPU
• the regression tests
  • [x] on GPU
  • [x] on CPU

Additional background

Issue Number:

[moprak-nrel]

My CPU/GPU regtests pass as well

100% tests passed, 0 tests failed out of 87

Label Time Summary:
no_ci         = 578.02 sec*proc (81 tests)
regression    = 609.66 sec*proc (86 tests)
unit          = 191.35 sec*proc (1 test)

Total Test time (real) = 801.09 sec