docs(CommitmentPolicy): Detail Commitment Policy on Enum (#913)

Author: texastony

src/main/java/com/amazonaws/encryptionsdk/CommitmentPolicy.java

@@ -3,11 +3,30 @@
 
 package com.amazonaws.encryptionsdk;
 
+/**
+ * Governs how a AwsCrypto behaves during configuration, encryption, and decryption, with respect to
+ * key commitment.
+ */
 public enum CommitmentPolicy {
+  /**
+   * On encrypty, algorithm suite must NOT support key commitment; On decrypt, if a key commitment
+   * is present on the ciphertext, then the key commitment must be valid. Key commitment will NOT be
+   * included in ciphertext on encrypt.
+   */
   ForbidEncryptAllowDecrypt,
+  /**
+   * On encrypt, algorithm suite must support key commitment; On decrypt, if a key commitment is
+   * present on the ciphertext, then the key commitment must be valid. Key commitment will be
+   * included in ciphertext on encrypt.
+   */
   RequireEncryptAllowDecrypt,
+  /**
+   * Algorithm suite must support key commitment. Key commitment will be included in ciphertext on
+   * encrypt. Valid key commitment must be present in ciphertext on decrypt.
+   */
   RequireEncryptRequireDecrypt;
 
+  /** Validates that an algorithm meets the Policy's On encrypt key commitment. */
   public boolean algorithmAllowedForEncrypt(CryptoAlgorithm algorithm) {
     switch (this) {
       case ForbidEncryptAllowDecrypt:
@@ -21,6 +40,7 @@ public boolean algorithmAllowedForEncrypt(CryptoAlgorithm algorithm) {
     }
   }
 
+  /** Validates that an algorithm meets the Policy's On decrypt key commitment. */
   public boolean algorithmAllowedForDecrypt(CryptoAlgorithm algorithm) {
     switch (this) {
       case ForbidEncryptAllowDecrypt: