Provide BCC in WVDrmFactory dumpsys.

[ Merge of go/wvgerrit/c/cdm/+/165138 ]

Enabled the Widevine DRM service on Android to return the raw boot
certificate chain via the CDM status query capabilities.  This
property key is not available for app-level queries.

The BCC is dumped by the WVDrmFactory when requested to print all
CDM properties via dumpsys.

Bug: 234095402
Test: request_license_test
Test: adb shell dumpsys android.hardware.drm.IDrmFactory/widevine -p
Change-Id: I34695b0655b4c609979577e9986974bc0fbda898

libwvdrmengine/src/WVDrmFactory.cpp

@@ -10,6 +10,7 @@
 #include "WVDrmFactory.h"
 
 #include <cctype>
+#include <algorithm>
 
 #include <android/binder_ibinder_platform.h>
 #include <binder/IPCThreadState.h>
@@ -154,19 +155,12 @@ int32_t WVDrmFactory::firstApiLevel() {
   return ::ndk::ScopedAStatus::ok();
 }
 
-string WVDrmFactory::stringToHex(const string& s) {
-  string input(s.c_str());
-  bool toHex = false;
-  for (const char ch : input) {
-    if (!isprint(ch)) {
-      toHex = true;
-      break;
-    }
+string WVDrmFactory::stringToHex(const string& input) {
+  if (std::all_of(input.begin(), input.end(), ::isprint)) {
+    return input;
   }
-  if (!toHex) return input;
 
   static constexpr char hex[] = "0123456789ABCDEF";
-
   string output;
   output.reserve(input.length() * 2);
   for (const unsigned char ch : input) {
@@ -247,6 +241,9 @@ void WVDrmFactory::printCdmProperties(int fd) {
        wvcdm::QUERY_KEY_CAN_DISABLE_ANALOG_OUTPUT},
       {"watermarking_support", wvcdm::QUERY_KEY_WATERMARKING_SUPPORT},
       {"production_ready", wvcdm::QUERY_KEY_PRODUCTION_READY},
+      // Debug properties.  Not exposed to app.
+      {"boot_certificate_chain",
+       wvcdm::QUERY_KEY_DEBUG_BOOT_CERTIFICATE_CHAIN},
   };
 
   string value;