Allow the launcher to select the GLES implementation

BUG: 128842306
Test: Local build, boot 3 ways
Change-Id: I4d0ddf722f4b0868c484606e50b6daafb2dc1153
diff --git a/host/commands/launch/flags.cc b/host/commands/launch/flags.cc
index a761a74..ed50269 100644
--- a/host/commands/launch/flags.cc
+++ b/host/commands/launch/flags.cc
@@ -88,10 +88,10 @@
     vm_manager, vm_manager::CrosvmManager::name(),
     "What virtual machine manager to use, one of {qemu_cli, crosvm}");
 DEFINE_string(
-    gpu_mode, vsoc::kGpuModeGuestAshmem,
-    "What gpu configuration to use, one of {guest_ashmem, guest_drm}");
+    gpu_mode, vsoc::kGpuModeGuestSwiftshader,
+    "What gpu configuration to use, one of {guest_swiftshader, drm_virgl}");
 DEFINE_string(wayland_socket, "",
-    "Location of the wayland socket to use for *_drm gpu_modes.");
+    "Location of the wayland socket to use for drm_virgl gpu_mode.");
 
 DEFINE_string(system_image_dir, vsoc::DefaultGuestImagePath(""),
               "Location of the system partition images.");
@@ -281,9 +281,6 @@
   }
   tmp_config_obj.set_wayland_socket(FLAGS_wayland_socket);
 
-  // TODO(b/77276633): This should be handled as part of the GPU configuration
-  tmp_config_obj.add_kernel_cmdline("androidboot.hardware.egl=swiftshader");
-
   vm_manager::VmManager::ConfigureBootDevices(&tmp_config_obj);
 
   tmp_config_obj.set_serial_number(FLAGS_serial_number);