make incremental blueberry testing faster

don't rebuild everything and unzip, instead

only build the specific targets we care about, copy them over directly
skips a lot of build time

Bug: 171749953
Tag: #gd-refactor
Test: gd/cert/run --rhost
Change-Id: I11e82e178e3901f9af46a510adbced8f1b3333a5