[FIX] Adding retentionEnabledDefault check before showing warning message

[yash-rajpal]

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Proposed changes (including videos or screenshots)

Added check for retentionEnabledDefault before showing prune warning message.

Issue(s)

fixes #20685

Steps to test or reproduce

Check issue

Further comments

Before showing message in RoomInfo, we were only checking for global retentionPolicyEnabled, we were not checking for the channel or dm or group policy. So added check for that.

So when these 3 are off, warning should not be shown in respective types of channels.

[yash-rajpal]

Also fixed sentence a bit, as described in issue, "days" word was missing after number of days

[yash-rajpal]

@ggazzo @dougfabris this pr is ready for review. :)

[yash-rajpal]

@ggazzo @dougfabris Please have a look. Thanks :)