Drop timestamp checks in Remote Config

[Skoti]

Feature proposal

• Firebase Component: Remote Config

I've noticed that remote config updates rely on the lastApplyTimeInterval and lastETagUpdateTime.
This means that if a user changes a date in their phone to a future date (for whatever reason), run an app and got a remote config update, it will set lastApplyTimeInterval to future timestamp:

firebase-ios-sdk/FirebaseRemoteConfig/Sources/FIRRemoteConfig.m

Line 317 in a2fbd12

strongSelf->_settings.lastApplyTimeInterval = [[NSDate date] timeIntervalSince1970];

Then if they change a date to the real one (which in that case is an earlier one) then any new remote config updates will be ignored due to this check:

firebase-ios-sdk/FirebaseRemoteConfig/Sources/FIRRemoteConfig.m

Lines 296 to 299 in a2fbd12

	if (strongSelf->_settings.lastETagUpdateTime == 0 ||
	strongSelf->_settings.lastETagUpdateTime <= strongSelf->_settings.lastApplyTimeInterval) {
	FIRLogWarning(kFIRLoggerRemoteConfig, @"I-RCN000069",
	@"Most recently fetched config is already activated.");

This means users will be unable to activate any future remote config updates up to that future date they had set unless they reinstall the app.

Wouldn't it be better if the remote config updates relied only on some config version check which I guess could be the etag itself?

[google-oss-bot]

I found a few problems with this issue:

• I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.
• This issue does not seem to follow the issue template. Make sure you provide all the required information.