docs: Added documentation about handling #1374 issue

docs/bugs/1374_invalid_class.md

@@ -0,0 +1,75 @@
+# [Parametrized tests] #1374 - java.lang.ClassNotFoundException: Invalid name: 
+
+## Bug description
+
+Test code with parametrized code and custom name
+
+```kotlin
+@RunWith(Parameterized::class)
+class BrokenTestName2(private val testCase: TestCase) {
+
+    @Test fun test() {
+        val expectedRemainder = if (testCase.odd) 1 else 0
+        for (value in testCase.values) {
+            assertEquals(expectedRemainder, abs(value % 2))
+        }
+    }
+
+    data class TestCase(
+        val values: List<Int>,
+        val odd: Boolean,
+    )
+
+    companion object {
+
+        @[JvmStatic Parameterized.Parameters(name = "{0}")]
+        fun parameters(): List<TestCase> = listOf(
+            TestCase(listOf(-4, -2, 0, 2, 4), odd = false),
+            TestCase(listOf(-3, -5, -1, 1, 3, 5), odd = true),
+        )
+    }
+}
+```
+
+Will produce failures such as:
+```
+java.lang.ClassNotFoundException: Invalid name:  3
+at java.lang.Class.classForName(Native Method)
+at java.lang.Class.forName(Class.java:324)
+at androidx.test.internal.runner.TestLoader.doCreateRunner(TestLoader.java:72)
+at androidx.test.internal.runner.TestLoader.getRunnersFor(TestLoader.java:105)
+at androidx.test.internal.runner.TestRequestBuilder.build(TestRequestBuilder.java:804)
+at androidx.test.runner.AndroidJUnitRunner.buildRequest(AndroidJUnitRunner.java:575)
+at androidx.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:393)
+at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1879)
+```
+
+and similar failures for other values interspersed with commas, e.g. `java.lang.ClassNotFoundException: Invalid name:  -2`, etc.
+
+Such failures appear like this in the FTL UI:
+
+![image](https://user-images.githubusercontent.com/2455337/101087202-bedca680-3566-11eb-918a-c34b123e803d.png)
+
+## Test details
+
+No matter if sharding is disabled or not, tests will always fail both on GCloud and Flank
+
+## Solution
+
+Disable test orchestrator with yaml option:
+```yaml
+gcloud:
+  ...
+  use-orchestrator: false
+  ...
+flank:
+  ...
+```
+or CLI command:
+```
+--no-use-orchestrator
+```
+
+## More info
+
+Please take a look at [documentation about sharding](https://github.com/Flank/flank/blob/master/docs/test_sharding.md#parameterized-tests) for more info