api,stub:Stabilize part of compression agreed to in the stabilization meeting (#9942)

* api,stub:Stabilize part of compression agreed to in the stabilization meeting.

addresses part of #1704
diff --git a/api/src/main/java/io/grpc/CallOptions.java b/api/src/main/java/io/grpc/CallOptions.java
index 4b180c5..87493d2 100644
--- a/api/src/main/java/io/grpc/CallOptions.java
+++ b/api/src/main/java/io/grpc/CallOptions.java
@@ -138,13 +138,12 @@
 
   /**
    * Sets the compression to use for the call.  The compressor must be a valid name known in the
-   * {@link CompressorRegistry}.
+   * {@link CompressorRegistry}.  By default, the "gzip" compressor will be available.
    *
    * <p>It is only safe to call this if the server supports the compression format chosen. There is
    * no negotiation performed; if the server does not support the compression chosen, the call will
    * fail.
    */
-  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1704")
   public CallOptions withCompression(@Nullable String compressorName) {
     Builder builder = toBuilder(this);
     builder.compressorName = compressorName;
@@ -207,7 +206,6 @@
   /**
    * Returns the compressor's name.
    */
-  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1704")
   @Nullable
   public String getCompressor() {
     return compressorName;
diff --git a/api/src/main/java/io/grpc/ServerCall.java b/api/src/main/java/io/grpc/ServerCall.java
index 40bcd2f..bf0e6da 100644
--- a/api/src/main/java/io/grpc/ServerCall.java
+++ b/api/src/main/java/io/grpc/ServerCall.java
@@ -189,16 +189,15 @@
    * encoding has been negotiated, this is a no-op. By default per-message compression is enabled,
    * but may not have any effect if compression is not enabled on the call.
    */
-  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1704")
   public void setMessageCompression(boolean enabled) {
     // noop
   }
 
   /**
-   * Sets the compression algorithm for this call.  If the server does not support the compression
-   * algorithm, the call will fail.  This method may only be called before {@link #sendHeaders}.
-   * The compressor to use will be looked up in the {@link CompressorRegistry}.  Default gRPC
-   * servers support the "gzip" compressor.
+   * Sets the compression algorithm for this call.  This compression is utilized for sending.  If
+   * the server does not support the compression algorithm, the call will fail.  This method may
+   * only be called before {@link #sendHeaders}.  The compressor to use will be looked up in the
+   * {@link CompressorRegistry}.  Default gRPC servers support the "gzip" compressor.
    *
    * <p>It is safe to call this even if the client does not support the compression format chosen.
    * The implementation will handle negotiation with the client and may fall back to no compression.
@@ -206,7 +205,6 @@
    * @param compressor the name of the compressor to use.
    * @throws IllegalArgumentException if the compressor name can not be found.
    */
-  @ExperimentalApi("https://github.com/grpc/grpc-java/issues/1704")
   public void setCompression(String compressor) {
     // noop
   }