[Android] Add top site and brave suggested site suggestion settings on Android

[bbondy]

Please add 2 new toggles in Android suggestions for controlling the prefs: kTopSiteSuggestionsEnabled
and kBraveSuggestedSiteSuggestionsEnabled.

It is to control the URL bar suggestions that come up.

The strings for them exist already for desktop in IDS_SETTINGS_APPEARANCE_SETTINGS_USE_AUTOCOMPLETE_TOP_SITES and
IDS_SETTINGS_APPEARANCE_SETTINGS_USE_AUTOCOMPLETE_BRAVE_SUGGESTED_SITES in app/brave_generated_resources.grd

It is needed for 1.9.x, Basically there are some new suggestions that we populate for brave suggested sites like "Bitcoin" to give a link to buy bitcoin on Binance with a referral code.

The new suggestions FYI are these: https://github.com/brave/brave-core/blob/master/components/omnibox/browser/suggested_sites_provider_data.cc#L13

The default of the toggles is to be on.
The work for Suggested sites is all done here #9302
This is just a toggle to be able to turn it off from the Android side.

[srirambv]

Verification passed on OnePlus 6T with Android 10 running 1.9.77 x64 RC build

• Verified 2 new entries for Show top sites in autocomplete and Show suggested sites in autocomplete under privacy
• Verified disabling Show top sites in autocomplete disables Alexa suggestions
• Verified disabling Show suggested sites in autocomplete disables Brave suggested sites
• Verified settings work on both normal and private tabs

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Verification passed on Samsung Tab A with Android 9 running 1.9.77 x64 RC build

• Verified 2 new entries for Show top sites in autocomplete and Show suggested sites in autocomplete under privacy
• Verified disabling Show top sites in autocomplete disables Alexa suggestions
• Verified disabling Show suggested sites in autocomplete disables Brave suggested sites
• Verified settings work on both normal and private tabs

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Verification passed on Asus Zenfone (x86) with Android 6 running BraveModernx86.apk 1.9.77 RC build

• Verified 2 new entries for Show top sites in autocomplete and Show suggested sites in autocomplete under privacy
• Verified disabling Show top sites in autocomplete disables Alexa suggestions
• Verified disabling Show suggested sites in autocomplete disables Brave suggested sites
• Verified settings work on both normal and private tabs