Make javadoc <p> style guide compliant

This led to confusion for an open source contributor about how to format
code. We don't want to be like, "do as I say, not as I do."

https://google.github.io/styleguide/javaguide.html#s7.1.2-javadoc-paragraphs
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=122589700

java/google/registry/model/domain/fee/BaseFeeCommand.java

@@ -32,8 +32,8 @@ public class BaseFeeCommand extends ImmutableObject {
 
   /**
    * The magnitude of the fee, in the specified units, with an optional description.
-   * <p>
-   * This is a list because a single operation can involve multiple fees.
+   *
+   * <p>This is a list because a single operation can involve multiple fees.
    */
   @XmlElement(name = "fee")
   List<Fee> fees;