APM dump: Indent the name of the USB device properly

Example output:

   2. Port ID: 30; "USB Headset Out"; {AUDIO_DEVICE_OUT_USB_...
      Encapsulation modes: 0, metadata types: 0
      "USB-Audio - HIFI DSD"

Bug: 231976949
Test: adb shell dumpsys media.audio_policy
Change-Id: I2cbcf0bba596d36227b38d60aedf3baa383b9404
diff --git a/media/libaudiofoundation/DeviceDescriptorBase.cpp b/media/libaudiofoundation/DeviceDescriptorBase.cpp
index 5ffbffc..91efb96 100644
--- a/media/libaudiofoundation/DeviceDescriptorBase.cpp
+++ b/media/libaudiofoundation/DeviceDescriptorBase.cpp
@@ -126,7 +126,14 @@
                     "%*sEncapsulation modes: %u, metadata types: %u\n", spaces, "",
                     mEncapsulationModes, mEncapsulationMetadataTypes));
 
-    AudioPort::dump(dst, spaces, nullptr, verbose);
+    std::string portStr;
+    AudioPort::dump(&portStr, spaces, nullptr, verbose);
+    if (!portStr.empty()) {
+        if (!mName.empty()) {
+            dst->append(base::StringPrintf("%*s", spaces, ""));
+        }
+        dst->append(portStr);
+    }
 }
 
 std::string DeviceDescriptorBase::toString(bool includeSensitiveInfo) const