Add first wearable sample to sdk samples distribution

Wearable samples sometimes have special gradle setups that nest
one application within another. As such, inclusion in the existing
samples generator may be tricky. Instead, just prepare the sample
for direct inclusion into the sdk distribution.

Create a convenience gradle build to build all wearable samples
at once.

Bug: 15591212
Change-Id: I6e03f7c5cc87909430b927aca4b403ded77917ab
88 files changed