api: create/register/upload template with empty template tag (apache#12234)

Author: weizhouapache

api/src/main/java/org/apache/cloudstack/api/command/user/template/CreateTemplateCmd.java

@@ -211,7 +211,7 @@ public String getUrl() {
     }
 
     public String getTemplateTag() {
-        return templateTag;
+        return StringUtils.isBlank(templateTag) ? null : templateTag;
     }
 
     public Map getDetails() {

api/src/main/java/org/apache/cloudstack/api/command/user/template/GetUploadParamsForTemplateCmd.java

@@ -170,7 +170,7 @@ public Boolean isSshKeyEnabled() {
     }
 
     public String getTemplateTag() {
-        return templateTag;
+        return StringUtils.isBlank(templateTag) ? null : templateTag;
     }
 
     public boolean isDeployAsIs() {

api/src/main/java/org/apache/cloudstack/api/command/user/template/RegisterTemplateCmd.java

@@ -279,7 +279,7 @@ public String getChecksum() {
     }
 
     public String getTemplateTag() {
-        return templateTag;
+        return StringUtils.isBlank(templateTag) ? null : templateTag;
     }
 
     public Map getDetails() {

server/src/main/java/com/cloud/consoleproxy/ConsoleProxyManagerImpl.java

@@ -736,7 +736,7 @@ protected Map<String, Object> createProxyInstance(long dataCenterId, List<VMTemp
                     logger.debug("Unable to allocate proxy {} with {} in {} due to [{}]. Retrying with another template", proxy, template, dc, e.getMessage(), e);
                     continue;
                 }
-                throw new CloudRuntimeException("Failed to allocate proxy [%s] in zone [%s] with available templates", e);
+                throw new CloudRuntimeException(String.format("Failed to allocate proxy [%s] in zone [%s] with available templates", proxy, dc), e);
             }
         }