Gradle v5.0 - execute() method renamed to exec()

[OleksandrKucherenko]

https://github.com/getsentry/react-native-sentry/blob/96f09af56c6a85e1548acf6fea45be6ef3d44a07/sentry.gradle#L176-L179

In latest Gradle Exec task has API changes. execute() method is no more available and should be replaced by exec();

Solution:

• its a wrong approach to call tasks directly from code, gradle has tasks graph and execute tasks according to it. Sentry script should just configure proper dependencies between the tasks and use one of the gradle tasks directives: finalizedBy, mustRunAfter, onlyIf, etc. (https://docs.gradle.org/current/dsl/org.gradle.api.Task.html)

[jussirantala]

Could you make a PR?

[OleksandrKucherenko]

@jussirantala ^

[OleksandrKucherenko]

@HazAT ^ - can you review the PR and merge?