Use cpp aidl_interface within statsd

This CL is part of a larger effort to shift statsd to libbinder_ndk.
This CL specifically accomplishes the following:
    - constructs an aidl_interface soong module that can be used by statsd
      and libstatspull
    - defines the parameters of StatsDimensionsValueParcel
      (conversions to and from StatsDimensionsValueParcel are not yet defined,
      so this CL will break sendSubscriberBroadcast. A later CL will fix this
      issue...)

Test: m -j
Bug: 148682447
Change-Id: I7afa3e21d4c9fc1970e6c393204e1bdb110760fb