Filters: Update Design to match iOS

[luke-freeman]

Update the filter dropdown design to match iOS for parity between the platforms

• Append count of filters added to the dropdown title eg. Platform · 2
• Remove show/hide label and have arrows on right hand side of dropdown
• Update button labels at bottom of filters to 'Reset Filters' and 'Apply Filters'

iOS filters for reference

Environment

• Android Version: 9
• raywenderlich.com App Version: 1.1.0
• Device: Galaxy S8