Improve Android scripts:

Improve Android scripts:

* android_gdbserver:
  - Don't complain if $GDB_TMP_DIR already exists
  - Since $GDB_TMP_DIR/gdb.setup might already exist, overwrite the file.

* android_run_skia:
  - Move resource files onto the device.
  - Change to tmp directory before executing program.

* android_make, android_setup:
  - stop assuming PWD is skia source directory.

NOTRY=true
R=djsollen@google.com, scroggo@google.com

Author: halcanary@google.com

Review URL: https://codereview.chromium.org/254923003

git-svn-id: http://skia.googlecode.com/svn/trunk@14442 2bbb7eff-a529-9590-31e7-b0007b416f81