Adjust core-platform-api-stubs-system-modules

Include core-lambda-stubs in core-platform-api-stubs-system-modules.
This will be needed when compiling code containing lambdas against
core platform API stubs with the Java 9 compiler. The
core-system-modules it is replacing also contains core-lambda-stubs.

Bug: 113148576
Test: build
Change-Id: Ie0f4ad66762dc9cbfe87e4cf21672b7cce7f27a2