dragonboard: Make provision-device script usable outside tree.

Update script to support ANDROID_PROVISION_OS_PARTITONS and
ANDROID_PROVISION_VENDOR_PARTITIONS environment variables.

To test that this work outside the tree, I ran 'm dist' and unzipped the
resulting vendor_partitions.zip file in a temporary directory from a
fresh shell:

 ~$ mkdir tmp && cd tmp
 ~/tmp$ unzip /ssd/android/out/dist/dragonboard-vendor_partitions-eng.zeuthen.zip
 ~/tmp$ find .
 .
 ./vendor_partitions
 ./vendor_partitions/modemst2.bin
 ./vendor_partitions/modem.bin
 ./vendor_partitions/sec.bin
 ./vendor_partitions/fsc.bin
 ./vendor_partitions/DDR.bin
 ./vendor_partitions/rpm.bin
 ./vendor_partitions/hyp.bin
 ./vendor_partitions/modemst1.bin
 ./vendor_partitions/aboot.bin
 ./vendor_partitions/sbl1.bin
 ./vendor_partitions/tz.bin
 ./vendor_partitions/fsg.bin
 ./partitions
 ./partitions/partition-tables.bin
 ./partitions/misc.bin
 ./provision-device
 ~/tmp$ PATH=/ssd/android/out/host/linux-x86/bin
 ANDROID_PROVISION_OS_PARTITIONS=/ssd/android/out/target/product/dragonboard
 ANDROID_PROVISION_VENDOR_PARTITIONS=$(pwd) ./provision-device
 target reported max download size of 268435456 bytes
 sending 'partition' (33 KB)...
 OKAY [  0.008s]
 writing 'partition'...
 OKAY [  0.331s]
 sending 'modem' (65536 KB)...
 OKAY [  2.557s]
 writing 'modem'...
 OKAY [  1.781s]
 sending 'fsc' (1 KB)...

 [...]

 OKAY [  1.026s]
 writing 'userdata'...
 OKAY [  1.925s]
 finished. total time: 30.983s
 ~/tmp$

which demonstrates it works as expected. In e.g. the lab, the fastboot
command would be part of the lab and ANDROID_PROVISION_OS_PARTITIONS
would come from e.g. target_files.zip or img.zip.

I also ran the 'provision' command inside the build environment to check
that provisioing still works in the inside-tree case.

Bug: 25648550
Change-Id: I6fb82f7dc36c169fd9cc5998626b93414c7f5e68
Test: Manually tested (see above).
1 file changed