patch google symptom early 2017-08-15 - 2020-02-19

[aysim319]

In the API, we only have them starting Feb 2020, but Google added earlier dates at some point starting from mid 2017

[aysim319]

county level

    select
        min(date),
       max(date)
    from `bigquery-public-data.covid19_symptom_search.symptom_search_sub_region_2_daily`
    where 
    timestamp(date) between timestamp("2017-01-01") and timestamp("2018-01-01") and
        country_region_code = "US"

state level

    select
        min(date),
       max(date)
    from `bigquery-public-data.covid19_symptom_search.symptom_search_sub_region_1_daily`
    where 
    timestamp(date) between timestamp("2017-01-01") and timestamp("2018-01-01") and
        country_region_code = "US"

returned [2017-08-15,2025-01-12]