Clarify search suggestions toggle and expand on-device functionality beyond Google

[ShivanKaul]

Description

If Show search suggestions is turned off in brave://settings/search, we still use an on-device model to generate suggestions based on what the user is typing in the omnibox. However, we only do this for Google. Also, the current text is not super clear.

PROPOSAL:

1. Use on-device model no matter what the default search engine is (not just Google)
2. Change toggle label and description to be:

Toggle name: Improve search suggestions
Toggle description: When on, Brave sends what you type in the address bar or search box to your default search engine to get better suggestions. When off, Brave only shows suggestions generated on your device. This is always off in private windows.

Steps to reproduce

1. Go to brave://settings/search
2. Check Show search suggestions toggle and description
3. Turn OFF
4. See if you get search suggestions using local model (i.e. no new network requests to any search engine)
5. Try with a few different default search engines (including Google)

Actual result

1. Currently the toggle text is not completely accurate (we still "show" search suggestions if the toggle is off using the local model when Google is the default search provider, and the description is correct but not complete)
2. We only use the local model if default search engine is Google

Expected result

See PROPOSAL above.

Reproduces how often

Easily reproduced

Brave version (brave://version info)

1.77.5 Chromium: 133.0.6943.39 (Official Build) nightly (arm64)

Channel information

• release (stable)
• beta
• nightly

Reproducibility

• with Brave Shields disabled
• with Brave Rewards disabled
• in the latest version of Chrome

Miscellaneous information

No response