Include the major version in update_engine.conf

This patch moves all the payload definition version numbers to
payload_constants.h and exposes the supported one in the .conf file.

Bug: 23946683
Test: Added unittest to match the .conf file with the code.

Change-Id: I7d84d2aa3c85d2b4d5da8bf102aa9bf99acc0136
diff --git a/delta_performer_integration_test.cc b/delta_performer_integration_test.cc
index 4a2505c..1e3dea8 100644
--- a/delta_performer_integration_test.cc
+++ b/delta_performer_integration_test.cc
@@ -910,7 +910,7 @@
 void DoOperationHashMismatchTest(OperationHashTest op_hash_test,
                                  bool hash_checks_mandatory) {
   DeltaState state;
-  uint64_t minor_version = DeltaPerformer::kFullPayloadMinorVersion;
+  uint64_t minor_version = kFullPayloadMinorVersion;
   GenerateDeltaFile(true, true, false, -1, kSignatureGenerated, &state,
                     minor_version);
   ScopedPathUnlinker a_img_unlinker(state.a_img);
@@ -955,7 +955,7 @@
 
 TEST(DeltaPerformerIntegrationTest, RunAsRootFullSmallImageTest) {
   DoSmallImageTest(true, true, false, -1, kSignatureGenerator,
-                   true, DeltaPerformer::kFullPayloadMinorVersion);
+                   true, kFullPayloadMinorVersion);
 }
 
 TEST(DeltaPerformerIntegrationTest, RunAsRootNoopSmallImageTest) {