Remove <impl> tag from ManifestHal.

It is deprecated as suggested by documentation.
Test: libvintf_test

Bug: 36602724

Change-Id: Ifc847f87f654b0c62dba6106ae5b19c9c2d87f30
diff --git a/parse_string.cpp b/parse_string.cpp
index f6ecc31..cec3adf 100644
--- a/parse_string.cpp
+++ b/parse_string.cpp
@@ -92,7 +92,6 @@
     }                                                              \
 
 DEFINE_PARSE_STREAMIN_FOR_ENUM(HalFormat);
-DEFINE_PARSE_STREAMIN_FOR_ENUM(ImplLevel);
 DEFINE_PARSE_STREAMIN_FOR_ENUM(Transport);
 DEFINE_PARSE_STREAMIN_FOR_ENUM(Arch);
 DEFINE_PARSE_STREAMIN_FOR_ENUM(KernelConfigType);
@@ -270,7 +269,7 @@
 
 bool parse(const std::string &s, ManifestHal *hal) {
     std::vector<std::string> v = SplitString(s, '/');
-    if (v.size() != 5) {
+    if (v.size() != 4) {
         return false;
     }
     if (!parse(v[0], &hal->format)) {
@@ -280,11 +279,7 @@
     if (!parse(v[2], &hal->transportArch)) {
         return false;
     }
-    if (!parse(v[3], &hal->impl.implLevel)) {
-        return false;
-    }
-    hal->impl.impl = v[4];
-    if (!parse(v[5], &hal->versions)) {
+    if (!parse(v[3], &hal->versions)) {
         return false;
     }
     return hal->isValid();
@@ -294,8 +289,6 @@
     return os << hal.format << "/"
               << hal.name << "/"
               << hal.transportArch << "/"
-              << hal.impl.implLevel << "/"
-              << hal.impl.impl << "/"
               << hal.versions;
 }