Use /data/mediadrm for MediaDrm plugin-related storage

related-to-bug: 8702754

Merge of:

Rename Keybox File
https://widevine-internal-review.googlesource.com/#/c/5240/

Store persistent data in /data/mediadrm
https://widevine-internal-review.googlesource.com/#/c/5234/

...from Widevine CDM repository

Change-Id: I4030257942e572e6f42cc8f32872a6409d9e3892

libwvdrmengine/cdm/core/src/device_files.cpp

@@ -14,9 +14,9 @@
 namespace wvcdm {
 
 // TODO(rfrias): Make this work for non-unix paths
-const char* DeviceFiles::kBasePath = "/data/drm";
-const char* DeviceFiles::kIdmPath = "/data/drm/IDM";
-const char* DeviceFiles::kCencPath = "/data/drm/IDM/CENC";
+const char* DeviceFiles::kBasePath = "/data/mediadrm";
+const char* DeviceFiles::kIdmPath = "/data/mediadrm/IDM";
+const char* DeviceFiles::kCencPath = "/data/mediadrm/IDM/CENC";
 const char* DeviceFiles::kDeviceCertificateFileName = "cert.bin";
 
 // Protobuf generated classes.

libwvdrmengine/cdm/core/test/file_store_unittest.cpp

@@ -5,11 +5,11 @@
 
 namespace {
   // TODO(rfrias): Make this work for non-unix paths
-  const std::string kDataDrmDir = "/data/drm";
-  const std::string kIdmTestDir = "/data/drm/IDMtest";
-  const std::string kCencTestDir = "/data/drm/IDMtest/CENCtest";
-  const std::string kCencTestDirWithSlash = "/data/drm/IDMtest/CENCtest/";
-  const std::string kTestFile01 = "/data/drm/IDMtest/CENCtest/file01.txt";
+  const std::string kDataDrmDir = "/data/mediadrm";
+  const std::string kIdmTestDir = "/data/mediadrm/IDMtest";
+  const std::string kCencTestDir = "/data/mediadrm/IDMtest/CENCtest";
+  const std::string kCencTestDirWithSlash = "/data/mediadrm/IDMtest/CENCtest/";
+  const std::string kTestFile01 = "/data/mediadrm/IDMtest/CENCtest/file01.txt";
 
   const std::string kFileExists = "/system/bin/sh";
   const std::string kDirExists = "/system/bin";