Fix: able to search tabs/history when the length of the search term >= 2

[cooltey]

In the logic block of searching tabs/history, the condition is searchTerm.length > 2. It makes sense for English but not non-English articles (e.g. Chinese). For example, "Captial" in Chinese is "首府", and the length is 2.

Also, in the getSearchResultsFromTabs, the logic is searchTerm.length >= 2, which is inconsistent with the one in the prefixSearch if block.

Bug: T364351