Shorten the name for the dump file.

The file name is getting truncated by tradefed and
we are missing the information to actually idenity
the test. So, instead shorten the filename to preserve
the test name.

Test: atest ./tests/cts/hostside/src/com/android/cts/net/HostsideRestrictBackgroundNetworkTests.java
Ignore-AOSP-First: Submitting internally first to avoid merge conflicts.
Merged-In: Ic0f87b97bb58e115fe81e2d688ce0e633397da42
Change-Id: I6ce3fc662782de82d8cad95414e24204b5f7f130

tests/cts/hostside/app/src/com/android/cts/net/hostside/DumpOnFailureRule.java

@@ -24,6 +24,8 @@ import android.os.FileUtils;
 import android.os.ParcelFileDescriptor;
 import android.util.Log;
 
+import androidx.test.platform.app.InstrumentationRegistry;
+
 import com.android.compatibility.common.util.OnFailureRule;
 
 import org.junit.AssumptionViolatedException;
@@ -37,23 +39,20 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 
-import androidx.test.platform.app.InstrumentationRegistry;
-
 public class DumpOnFailureRule extends OnFailureRule {
     private File mDumpDir = new File(Environment.getExternalStorageDirectory(),
             "CtsHostsideNetworkTests");
 
     @Override
     public void onTestFailure(Statement base, Description description, Throwable throwable) {
-        final String testName = description.getClassName() + "_" + description.getMethodName();
-
         if (throwable instanceof AssumptionViolatedException) {
+            final String testName = description.getClassName() + "_" + description.getMethodName();
             Log.d(TAG, "Skipping test " + testName + ": " + throwable);
             return;
         }
 
         prepareDumpRootDir();
-        final File dumpFile = new File(mDumpDir, "dump-" + testName);
+        final File dumpFile = new File(mDumpDir, "dump-" + getShortenedTestName(description));
         Log.i(TAG, "Dumping debug info for " + description + ": " + dumpFile.getPath());
         try (FileOutputStream out = new FileOutputStream(dumpFile)) {
             for (String cmd : new String[] {
@@ -71,6 +70,17 @@ public class DumpOnFailureRule extends OnFailureRule {
         }
     }
 
+    private String getShortenedTestName(Description description) {
+        final String qualifiedClassName = description.getClassName();
+        final String className = qualifiedClassName.substring(
+                qualifiedClassName.lastIndexOf(".") + 1);
+        final String shortenedClassName = className.chars()
+                .filter(Character::isUpperCase)
+                .collect(StringBuilder::new, StringBuilder::appendCodePoint, StringBuilder::append)
+                .toString();
+        return shortenedClassName + "_" + description.getMethodName();
+    }
+
     void dumpCommandOutput(FileOutputStream out, String cmd) {
         final ParcelFileDescriptor pfd = InstrumentationRegistry.getInstrumentation()
                 .getUiAutomation().executeShellCommand(cmd);