[ReactNative] Flatten margin styles causing "ghost" margins on FeedbackContent component

[alexruzenhack]

The following component FeedbackContent uses a flatten style method to aggregate conditional styles like offmargin, as you can see bellow:

<FeedbackContent
  message={t`Loading arguments.`}
  icon={<Spinner size={48} animating />}
  offmargin
/>

The offmargin flag sets a style to marginVertical: 0, while the component has a marginTop and marginBottom properties set. The the styles are flattened, the result is:

• The component FeedbackContent has its vertical margins zeroed.
• A "ghost" margin with the previous marginTop and marginBottom values remains rendered

The following image shows the gap between the title and the FeedbackContent component, while there is no margins or paddings applied:

The following image demonstrates the component's margins are zero.

By making other tests I have found a pattern:

• Overrinding properties works from general properties to specific properties, but not conversely

See the following Expo snack with the tests: https://snack.expo.dev/@alexruzenhack/margin-rules-application

I have fixed this issue in the following commit: https://github.com/HathorNetwork/hathor-wallet-mobile/pull/495/commits/5e90771c43cb7c7d795c493ee22114bb2e55f3fb