android/xts: add support for vts module level static sharding

[chase-qi]

It can useful when test setup is cheap and many DUTs are available for test runs in parallel.

Signed-off-by: Chase Qi chase.qi@linaro.org

[chase-qi]

Job example:

Run by a whole ltp module https://validation.linaro.org/scheduler/job/3848967, 1121 test results reported.

Shard ltp module into 3 shards.
shard3-1 https://validation.linaro.org/scheduler/job/3848962, 475 test results reported.
shard3-2 https://validation.linaro.org/results/3848964, 428 test results reported.
shard3-3 https://validation.linaro.org/scheduler/job/3849093 218 test results reported.
The overall test results reported by the 3 shards equal to 1121 which is the same as test run without sharding.

@liuyq @roxell @ivoire would you please help to review this MR?

[chase-qi]

splitting cts test config is a different story. I looked into the big cts test module testcases/CtsLibcoreTestCases/CtsLibcoreTestCases.config, I don't see individual tests in the config.

    <test class="com.android.compatibility.testtype.LibcoreTest" >
        <option name="package" value="android.libcore.cts" />
        <option name="instrumentation-arg" key="filter"
                value="com.android.cts.core.runner.ExpectationBasedFilter" />
        <option name="core-expectation" value="/knownfailures.txt" />
        <option name="virtual-device-core-expectation" value="/virtualdeviceknownfailures.txt" />
        <option name="runtime-hint" value="45m"/>
        <!-- 20x default timeout of 600sec -->
        <option name="shell-timeout" value="12000000"/>
        <option name="hidden-api-checks" value="false"/>
        <option name="device-listeners" value="org.conscrypt.ConscryptInstrumentationListener" />
        <option name="instrumentation-arg" key="conscrypt_sslsocket_implementation" value="engine" />
    </test>

More investigation is required to split cts test module. Not in this MR.