Update wearable samples to use new base-build template

Also sets wearable/has_handheld_app=true as necessary, to preserve existing
Application folders.

This corresponds with build changes in commit:
73bf080d2015c589a1f144ee697a51a6dcf751d4

Bug: 18353265
Change-Id: I6a45b1ec11bea4bbf3a178312f4e57e0b10f4167
20 files changed