Parse and expose end-of-life flag.
Omaha update or noupdate response can include _key=value pairs with
arbitrary data. One of those key can be "_eol" with the one of the
values "supported", "security-only" or "eol" which notifies the device
the end-of-life status of the device with respect to updates. This
information is now exposed via GetEolStatus() to the client so it
can be properly displayed in the UI.
Bug: 27924505
TEST=Added unittest. Run `update_engine_client --eol_status` on link.
Change-Id: Icc15f25b4d0b19cc894f5afc52ac7c43c7818982
diff --git a/common/constants.cc b/common/constants.cc
index f138ce3..c0bb874 100644
--- a/common/constants.cc
+++ b/common/constants.cc
@@ -57,6 +57,7 @@
const char kPrefsOmahaCohort[] = "omaha-cohort";
const char kPrefsOmahaCohortHint[] = "omaha-cohort-hint";
const char kPrefsOmahaCohortName[] = "omaha-cohort-name";
+const char kPrefsOmahaEolStatus[] = "omaha-eol-status";
const char kPrefsP2PEnabled[] = "p2p-enabled";
const char kPrefsP2PFirstAttemptTimestamp[] = "p2p-first-attempt-timestamp";
const char kPrefsP2PNumAttempts[] = "p2p-num-attempts";