Use the same name for local instance and directory

This commit changes the local instance directory name to be identical to
the instance name. When TradeFed creates local virtual device via
acloud, it can locate the directory by the instance name.

Test: acloud-dev create --local-instance --local-image
Test: acloud-dev create --avd-type goldfish \
      --local-instance --local-image
Bug: 133211308

Change-Id: I2b638e52f0d4d9f3d79079ca768230d9fd262254
4 files changed