[adb] Use incremental installation by default

This CL turns on the incremental installation for all
"adb install ..." commands where no explicit mode has been set.
To disable this, set the ADB_INSTALL_DEFAULT_INCREMENTAL
environment variable to 0/n/no/false. Unset to enable back

+ improve the install command argument parsing a bit: allow
  --wait for all installation modes, --incr is enough for
  an incremental install (and --no-incr to disable it)

Bug: 150183149
Test: adb install with different apks and command line switches
Change-Id: I1a237f34b70d920146746ab16104e28ef555a5fd