Fix some comments (thunderbird#8046)

Author: riskrose

mail/common/src/main/java/com/fsck/k9/mail/filter/Base64.java

@@ -473,7 +473,7 @@ void decode(byte[] in, int inPos, int inAvail) {
      *
      * @param octet
      *            The value to test
-     * @return <code>true</code> if the value is defined in the the base 64 alphabet, <code>false</code> otherwise.
+     * @return <code>true</code> if the value is defined in the base 64 alphabet, <code>false</code> otherwise.
      */
     public static boolean isBase64(byte octet) {
         return octet == PAD || (octet >= 0 && octet < base64ToInt.length && base64ToInt[octet] != -1);

mail/common/src/main/java/com/fsck/k9/mail/internet/MimeUtility.java

@@ -55,7 +55,7 @@ public static String unfoldAndDecode(String s, Message message) {
      * </p>
      * <p>
      * Note: Parsing header parameters is not a very cheap operation. Prefer using {@code MimeParameterDecoder}
-     * directly over calling this method multiple times for extracting different parameters from the the same header.
+     * directly over calling this method multiple times for extracting different parameters from the same header.
      * </p>
      *
      * @param headerBody The header body.

mail/protocols/imap/src/main/java/com/fsck/k9/mail/store/imap/RealImapFolder.kt

@@ -41,7 +41,7 @@ internal class RealImapFolder(
     private var uidValidity: Long? = null
 
     /**
-     * Specifies whether the folder was opened in read-only or read-write mode based on the the tagged OK response to
+     * Specifies whether the folder was opened in read-only or read-write mode based on the tagged OK response to
      * the SELECT or EXAMINE command (READ-ONLY or READ-WRITE).
      *
      * Most of the time this will match the [mode] value. But it's possible for the SELECT command to open a folder in

ui-utils/LinearLayoutManager/src/main/java/app/k9mail/ui/utils/linearlayoutmanager/LinearLayoutManager.java

@@ -1874,7 +1874,7 @@ View findFirstVisibleChildClosestToEnd(boolean completelyVisible,
      *                      (reverseLayout ^ stackFromEnd).
      * @param traverseChildrenInReverseOrder True if the children should be traversed in reverse
      *                                       order (stackFromEnd).
-     * @return A View that can be used an an anchor View.
+     * @return A View that can be used as an anchor View.
      */
     View findReferenceChild(RecyclerView.Recycler recycler, RecyclerView.State state,
             boolean layoutFromEnd, boolean traverseChildrenInReverseOrder) {