Fixes Android compilation error:
```
:RNMail:processReleaseJavaRes UP-TO-DATE
:RNMail:compileReleaseJavaWithJavac
/path/to/project/node_modules/react-native-mail/android/src/main/java/com/chirag/RNMail/RNMail.java:19: illegal start of type
List<NativeModule> modules = new ArrayList<>();
^
1 error
:RNMail:compileReleaseJavaWithJavac FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':RNMail:compileReleaseJavaWithJavac'.
> Compilation failed; see the compiler error output for details.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
BUILD FAILED
```
David Vacca