java_grpc_library.bzl: Fix parameters of java_common.compile (#7598)

Parameter host_javabase is removed.

This is preparation for flipping incompatible_java_common_parameters in
Bazel 5. See bazelbuild/bazel#12373

Bazel versions prior to 4 require host_javabase, so are no longer supported.

buildscripts/kokoro/bazel.sh

@@ -3,7 +3,7 @@
 set -exu -o pipefail
 cat /VERSION
 
-use_bazel.sh 1.0.1
+use_bazel.sh 4.0.0
 bazel version
 
 cd github/grpc-java

java_grpc_library.bzl

@@ -2,7 +2,6 @@
 
 _JavaRpcToolchainInfo = provider(
     fields = [
-        "host_javabase",
         "java_toolchain",
         "plugin",
         "plugin_arg",
@@ -14,7 +13,6 @@ _JavaRpcToolchainInfo = provider(
 def _java_rpc_toolchain_impl(ctx):
     return [
         _JavaRpcToolchainInfo(
-            host_javabase = ctx.attr._host_javabase,
             java_toolchain = ctx.attr._java_toolchain,
             plugin = ctx.executable.plugin,
             plugin_arg = ctx.attr.plugin_arg,
@@ -44,10 +42,6 @@ java_rpc_toolchain = rule(
         "_java_toolchain": attr.label(
             default = Label("@bazel_tools//tools/jdk:current_java_toolchain"),
         ),
-        "_host_javabase": attr.label(
-            cfg = "host",
-            default = Label("@bazel_tools//tools/jdk:current_java_runtime"),
-        ),
     },
     provides = [
         _JavaRpcToolchainInfo,
@@ -106,7 +100,6 @@ def _java_rpc_library_impl(ctx):
     java_info = java_common.compile(
         ctx,
         java_toolchain = toolchain.java_toolchain[java_common.JavaToolchainInfo],
-        host_javabase = toolchain.host_javabase[java_common.JavaRuntimeInfo],
         source_jars = [srcjar],
         output = ctx.outputs.jar,
         output_source_jar = ctx.outputs.srcjar,