pass the multiple platform flag to kotlin compiler

[ivyspirit]

We are building Kotlin multiple platform project, which need bazel to support building kotlin code with KMP features. -Xmulti-platform flag is needed to be passed to kotlinc compiler to avoid the compile errors.

Based on the statue of this issue there is no generic way of passing kotlinc compiler arguements. This PR add the arg to the kt_kotlinc_options so it can be enabled or disabled.

Test:
Tested with local local_repository, kmp code compile successful.
Before got error:
` error: the feature "multi platform projects" is experimental and should be enabled explicitly

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[ivyspirit]

@googlebot I signed it!

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[ivyspirit]

@googlebot I fixed it.