Fix adb not correctly reading return code from DeployAgent

Certain error conditions were getting lost because adb was wrongly
reading DeployAgent's return code as always 0.

Test: mm -j 72
Test: adb install -r --fastdeploy --force-agent --local-agent /mnt/raid/boat-attack-apk/boat-attack-swappy.apk

Bug: 120197330
Change-Id: If835fd6ca2051be8e5ff6c957e08b1e458053989