Move the CDM version string to a header file

[ Merge of http://go/wvgerrit/95943 ]

The CDM version for android is now defined in a platform specific
header file. A check for version number match has been removed
from integration tests as it will always be true. We will still
get a notification to change the CDM version when the Android OS
version gets updated.

Bug: 151663718
Test: WV unit/integration tests
Change-Id: I96bac87186e30a709585514be7f338ad2209cdf6

libwvdrmengine/cdm/include/wv_android_constants.h

@@ -0,0 +1,12 @@
+#ifndef WVCDM_WV_ANDROID_CONSTANTS_H_
+#define WVCDM_WV_ANDROID_CONSTANTS_H_
+
+#include <string>
+
+namespace wvcdm {
+
+static const std::string kWVAndroidCdmVersion = "16.0.0";
+
+}  // namespace wvcdm
+
+#endif  // WVCDM_WV_ANDROID_CONSTANTS_H_