ART: Remove experimental flags for plugins and agents

Remove experimental flags guarding plugins and agents.

Partial revert of commit 7233c7e752c0d26387d143ee74420e9cd1f09390.
Partial revert of commit 185d134a3b43ab7529053e965917e0fa74bceba4.

Bug: 31455788
Test: m test-art-host
Change-Id: I11a19f24b88ced8da7a28e2cb7a2f602aab884a8
diff --git a/runtime/runtime_options.def b/runtime/runtime_options.def
index 749a36e..ad748b0 100644
--- a/runtime/runtime_options.def
+++ b/runtime/runtime_options.def
@@ -119,10 +119,10 @@
 RUNTIME_OPTIONS_KEY (Unit,                NoDexFileFallback)
 RUNTIME_OPTIONS_KEY (std::string,         CpuAbiList)
 RUNTIME_OPTIONS_KEY (std::string,         Fingerprint)
-RUNTIME_OPTIONS_KEY (ExperimentalFlags,   Experimental,     ExperimentalFlags::kNone) // -Xexperimental:{none, agents}
-RUNTIME_OPTIONS_KEY (std::vector<ti::Agent>,         AgentLib)  // -agentlib:<libname>=<options>, Requires -Xexperimental:agents
-RUNTIME_OPTIONS_KEY (std::vector<ti::Agent>,         AgentPath)  // -agentpath:<libname>=<options>, Requires -Xexperimental:agents
-RUNTIME_OPTIONS_KEY (std::vector<Plugin>,            Plugins)  // -Xplugin:<library> Requires -Xexperimental:runtime-plugins
+RUNTIME_OPTIONS_KEY (ExperimentalFlags,   Experimental,     ExperimentalFlags::kNone) // -Xexperimental:{...}
+RUNTIME_OPTIONS_KEY (std::vector<ti::Agent>,         AgentLib)  // -agentlib:<libname>=<options>
+RUNTIME_OPTIONS_KEY (std::vector<ti::Agent>,         AgentPath)  // -agentpath:<libname>=<options>
+RUNTIME_OPTIONS_KEY (std::vector<Plugin>,            Plugins)  // -Xplugin:<library>
 RUNTIME_OPTIONS_KEY (Unit,                           FullyDeoptable)  // -Xfully-deoptable
 
 // Not parse-able from command line, but can be provided explicitly.