[ Merge of https://widevine-internal-review.googlesource.com/c/cdm/+/178890/ ] GetDeviceInformation() and GetDeviceSignedCsrPayload() are added to cdm_engine and crypto_session, so that they can be queried by DRM plugin. This is to allow the wv drm HAL to be able to extract BCC and CSR payload to build CSR for prov 4 device registration, such that we don't need a separate RKP HAL to do this job. Changes to the DRM plugin to use the exposed methods will be in the coming CL. Bug: 286556950 Test: request_license_test Change-Id: I5f7aed8b3471ea477b79d08b95e1d217dc39070b