[MBL-774] Use Cleaner Remote Config FetchAndActivate Approach

[scottkicks]

📲 What

• In order for the users to see changes to our Remote Config flags on first, or next, app launch we need to use RC's fetchAndActivate(_ completion:...) method.
• Our Alpha GoogleServices-Info.plist file needed to be replaced as well because RC requires that Real Time API be enabled in Google Cloud Services which updates the Firebase Project.

🤔 Why

Our implementation now activates previously cached values before fetching. This causes the newly fetched values to be cached for the next launch instead of being applied immediately.

🛠 How

Lets add the fetchAndComplete type signature to RemoteConfigClientType

func fetchAndActivate(completionHandler: ((RemoteConfigFetchAndActivateStatus, Error?) -> Void)?)

Then, we can replace the .fetch and .activate calls.

[codecov]

Codecov Report

Merging #1819 (b3b28c9) into main (6a48e5a) will decrease coverage by 0.01%.
The diff coverage is 70.00%.

❗ Current head b3b28c9 differs from pull request most recent head 04a2aee. Consider uploading reports for the commit 04a2aee to get more accurate results

@@            Coverage Diff             @@
##             main    #1819      +/-   ##
==========================================
- Coverage   84.46%   84.45%   -0.01%     
==========================================
  Files        1283     1283              
  Lines      116641   116650       +9     
  Branches    30947    30953       +6     
==========================================
+ Hits        98516    98521       +5     
- Misses      17047    17052       +5     
+ Partials     1078     1077       -1     

Impacted Files	Coverage Δ
Library/MockRemoteConfigClient.swift	42.85% <0.00%> (-3.30%)	⬇️
Library/RemoteConfig/RemoteConfigClientType.swift	100.00% <ø> (ø)
Library/RemoteConfig/RemoteConfligClient.swift	0.00% <0.00%> (ø)
...Models/RemoteConfigFeatureFlagToolsViewModel.swift	82.45% <100.00%> (+4.02%)	⬆️

... and 1 file with indirect coverage changes

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[msadoon]

good to go!