Upgrade gRPC and remove OkHttp dependency (#3975)

Author: tom-andersen

build.gradle

@@ -50,7 +50,7 @@ ext {
     playServicesVersion = '16.0.1'
     supportAnnotationsVersion = '28.0.0'
     googleTruthVersion = '1.1.2'
-    grpcVersion = '1.44.1'
+    grpcVersion = '1.48.1'
     robolectricVersion = '4.3.1'
     protocVersion = '3.17.3'
     javaliteVersion = '3.17.3'

firebase-firestore/firebase-firestore.gradle

@@ -148,7 +148,6 @@ dependencies {
     implementation 'com.google.android.gms:play-services-tasks:18.0.1'
     implementation 'com.google.android.gms:play-services-base:18.0.1'
 
-    implementation 'com.squareup.okhttp:okhttp:2.7.5'
     implementation('com.google.firebase:firebase-auth-interop:19.0.2') {
         exclude group: "com.google.firebase", module: "firebase-common"
     }