Let users use v1 without additional steps

[Szymon20000]

Fixes: #1838
Fixes: #1825
Fixes: #1798
We forgot To wrap some initialization steps of rea 2 into a condition that checks if the native side of reanimated 2 is available. Because of that people that want to use only v1 have to go through installation steps on Android.

Checklist

• Included code example that can be used to test this change
• Updated TS types
• Added TS types tests
• Added unit / integration tests
• Updated documentation
• Ensured that CI passes

[piaskowyk]

I tested and is ok.
Maybe we should change little the warn message

react-native-reanimated/src/reanimated2/core.js

Line 25 in 4ff075e

"Reanimated 2 failed to create a worklet, maybe you forgot to add Reanimated's babel plugin?"

to
Reanimated 2 failed to create a worklet, maybe you forgot to add Reanimated's babel plugin? If you want to use only Reanimated v1, you can ignore this message.

[satya164]

Unrelated to this PR, but is it possible to expose this in a public API? My use case is to do feature detection regarding if I can use the Reanimated 2 APIs and then use the new implementation if possible.

[piaskowyk]

@Szymon20000 What do you think?

[Szymon20000]

Sure