adb: add test for non-interactive stdin.

Add a test to send stdin to non-interactive `adb shell`.

This new test will hang on ToT devices that support shell_v2 until they
are rebuilt with the corresponding adb CL. A new feature could be added
instead to filter those devices out, but it doesn't seem worth it as no
devices have yet been released with shell_v2.

This CL also fixes a mistake I made earlier with device.linesep; this
is used to check device output, not separate device input. Using it
added unnecessary newline characters on Windows.

Bug: http://b/24565284
Change-Id: Ic123402975033d74688f56a36acac993af6815e6
1 file changed