Update UI for support tab.

Bug: 29397123
Bug: 29832054

- Increase spinner dropdown width to contain country names.
- Reduce suggestion counter's right padding.
- Tweak paddings in travel abroad phone dialog.
- Update icon and text for help&feedback / tips&tricks.

Change-Id: Ide52c6f8198d1a13a0fdeb000d7cb9e8c03688ca