Include jamm as runtime dependency in expansion-service

[Polber]

This PR allows a user to create a custom expansion service JAR without needing to provide jamm manually as a dependency.

e8cebdf added a dependency on ":sdks:java:harness" in the expansion service target which has a transitive dependency on a 'provided' jamm:

beam/sdks/java/harness/build.gradle

Line 40 in 33a0bfb

provided library.java.jamm

By adding it as a runtimeOnly dependency in the expansion service target, a user can create a cross-language Java transform by simply importing the beam-sdks-java-expansion-service JAR.

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[Polber]

R: @robertwb

[Polber]

R: @ahmedabu98

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