Allow specifying timeout second for HTTP2/2 health check

The env vars were implemented in kubernetes#95981.
Effectively no impacts if using the default values here.

BUG=255296578

Change-Id: I2441ef1a181a0fb202af7893c25cff5ff15ef17a

Remove GODEBUG=x509sha1=1 workaround

Bug: 227456358a

Revert changes made in I5165e6c2fe73e8e1b2a617ced591133228b6d275

Change-Id: I7dd1ca8f9796c542c89074703e44e6b6f4b6edab

gke/cluster/gce/gci/configure-kubeapiserver.sh

@@ -344,21 +344,17 @@ function start-kube-apiserver {
   fi
 
   local container_env=""
+
+  # b/255296578
+  container_env+="{\"name\": \"HTTP2_READ_IDLE_TIMEOUT_SECONDS\", \"value\": \"${KUBE_APISERVER_HTTP2_READ_IDLE_TIMEOUT_SECONDS:-30}\"}"
+  container_env+=",{\"name\": \"HTTP2_PING_TIMEOUT_SECONDS\", \"value\": \"${KUBE_APISERVER_HTTP2_PING_TIMEOUT_SECONDS:-15}\"}"
+
   if [[ -n "${ENABLE_CACHE_MUTATION_DETECTOR:-}" ]]; then
-    container_env+="{\"name\": \"KUBE_CACHE_MUTATION_DETECTOR\", \"value\": \"${ENABLE_CACHE_MUTATION_DETECTOR}\"}"
+    container_env+=",{\"name\": \"KUBE_CACHE_MUTATION_DETECTOR\", \"value\": \"${ENABLE_CACHE_MUTATION_DETECTOR}\"}"
   fi
   if [[ -n "${ENABLE_PATCH_CONVERSION_DETECTOR:-}" ]]; then
-    if [[ -n "${container_env}" ]]; then
-      container_env="${container_env}, "
-    fi
-    container_env+="{\"name\": \"KUBE_PATCH_CONVERSION_DETECTOR\", \"value\": \"${ENABLE_PATCH_CONVERSION_DETECTOR}\"}"
-  fi
-
-  # b/227456358
-  if [[ -n "${container_env}" ]]; then
-    container_env="${container_env}, "
+    container_env+=",{\"name\": \"KUBE_PATCH_CONVERSION_DETECTOR\", \"value\": \"${ENABLE_PATCH_CONVERSION_DETECTOR}\"}"
   fi
-  container_env+='{"name": "GODEBUG", "value": "x509sha1=1"}'
 
   if [[ -n "${container_env}" ]]; then
     container_env="\"env\":[${container_env}],"