[IMPROVEMENT] Convert UTC to time

[VANKINEENITAWRUN]

@RocketChat/android

Closes #2046

Changes: [converted the given UTC offset to time.]

Screenshots or GIF for the change:

[CLAassistant]

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[philipbrito]

Thanks for submitting this PR and closing the existent TODO here! But I think you could work with the Java 8 Date/Time API.

[philipbrito]

You can add a function on DateTimeHelper class to convert UTC to Time.

[philipbrito]

@VANKINEENITAWRUN Could you please sign in our CLA?

[VANKINEENITAWRUN]

I did @filipedelimabrito it's still pending.

[RotBolt]

You could Lift out the assignment timeZoneAlteredTime. Directly could
timeZoneAlteredTime = if (condition ) value else other value.
This would be according to Kotlin Coding style :)