Add #!/bin/bash header to bash files

[romayalon]

Explain the changes

1. The changed files were missing #!/bin/bash header which caused the following error while trying to build noobaa -
   Error while loading //./src/deploy/NVA_build/install_arrow_build.sh: Exec format error
   Fun Fact - it's called Shebang - https://en.wikipedia.org/wiki/Shebang_%28Unix%29

Issues: Fixed #xxx / Gap #xxx

Testing Instructions:

• Doc added/updated
• Tests added

[alphaprinz]

Thanks