Collect diagnostics without storage permission

Use the shell to open the output file instead of FileOutputStream. This
allows test to use ConnectivityDiagnosticsCollector even if they do not
have storage permissions.

getOutputStreamViaShell is a method of the base class
BaseMetricListener.

Bug: 317602748
Test: atest
Change-Id: I127bb6711d14fdee059a31a8a3cfddc44b1d7800
diff --git a/staticlibs/testutils/devicetests/com/android/testutils/ConnectivityDiagnosticsCollector.kt b/staticlibs/testutils/devicetests/com/android/testutils/ConnectivityDiagnosticsCollector.kt
index 4b9429b..07f3be5 100644
--- a/staticlibs/testutils/devicetests/com/android/testutils/ConnectivityDiagnosticsCollector.kt
+++ b/staticlibs/testutils/devicetests/com/android/testutils/ConnectivityDiagnosticsCollector.kt
@@ -45,7 +45,6 @@
 import java.io.ByteArrayOutputStream
 import java.io.CharArrayWriter
 import java.io.File
-import java.io.FileOutputStream
 import java.io.FileReader
 import java.io.OutputStream
 import java.io.OutputStreamWriter
@@ -280,7 +279,7 @@
         }
         val outFile = File(collectorDir, filename + FILENAME_SUFFIX)
         outputFiles.add(filename)
-        FileOutputStream(outFile).use { fos ->
+        getOutputStreamViaShell(outFile).use { fos ->
             failureHeader?.let {
                 fos.write(it.toByteArray())
                 fos.write("\n".toByteArray())