keystore2: Add timeout to RKPD get key call

Also replace libfutures with libtokio, as the former doesn't have
support for timeouts.

Bug: 264921138
Test: keystore2_test
Change-Id: I97c9749e93b2d001afe5d17bda8c665f884b0e05
diff --git a/keystore2/Android.bp b/keystore2/Android.bp
index fa80563..57038df 100644
--- a/keystore2/Android.bp
+++ b/keystore2/Android.bp
@@ -44,7 +44,6 @@
         "android.security.rkp_aidl-rust",
         "libanyhow",
         "libbinder_rs",
-        "libfutures",
         "libkeystore2_aaid-rust",
         "libkeystore2_apc_compat-rust",
         "libkeystore2_crypto_rust",
@@ -60,6 +59,7 @@
         "libserde",
         "libserde_cbor",
         "libthiserror",
+        "libtokio",
     ],
     shared_libs: [
         "libcutils",