Remove sun.security.x509 dependency

[merks]

The most recent version on Maven central

https://repo1.maven.org/maven2/org/conscrypt/conscrypt-openjdk-uber/2.5.2/

has an unfortunate Import-Package of of sun.security.x509

Automatic-Module-Name                   org.conscrypt
Bnd-LastModified                        1617109637399
BoringSSL-Version                       49f0329110a1d93a5febc2bceceedc655d995420
Built-By                                root
Built-JDK                               1.8.0_131
Bundle-ManifestVersion                  2
Bundle-Name                             org.conscrypt
Bundle-SymbolicName                     org.conscrypt
Bundle-Version                          2.5.2
Created-By                              1.8.0_131 (Oracle Corporation)
Export-Package                          org.conscrypt.ct;uses:="org.conscrypt";version="2.5.2"
                                        org.conscrypt.io;version="2.5.2"
                                        org.conscrypt;uses:="javax.crypto,javax.net.ssl,javax.security.auth.x500,org.conscrypt.ct";version="2.5.2"
Implementation-Title                    conscrypt-openjdk-uber
Implementation-Version                  2.5.2
Import-Package                          javax.crypto
                                        javax.crypto.spec
                                        javax.net
                                        javax.net.ssl
                                        javax.security.auth.x500
                                        javax.security.cert
                                        org.conscrypt
                                        org.conscrypt.ct
                                        org.conscrypt.io
                                        sun.security.x509
Manifest-Version                        1.0
Require-Capability                      osgi.ee;filter:="(&(osgi.ee=JavaSE)(version=1.7))"
Source-Compatibility                    1.7
Target-Compatibility                    1.7
Tool                                    Bnd-4.3.0.201909301554

I believe the comes from this import:

conscrypt/openjdk/src/main/java/org/conscrypt/Platform.java

Line 84 in 23ca210

import sun.security.x509.AlgorithmId;

which is used only in this method which is annotated as unused:

conscrypt/openjdk/src/main/java/org/conscrypt/Platform.java

Lines 537 to 550 in 23ca210

	/**
	* OID to Algorithm Name mapping.
	*/
	@SuppressWarnings("unused")
	static String oidToAlgorithmName(String oid) {
	try {
	return AlgorithmId.get(oid).getName();
	} catch (Exception e) {
	return oid;
	} catch (IllegalAccessError e) {
	// This can happen under JPMS because AlgorithmId isn't exported by java.base
	return oid;
	}
	}

Probably this can be removed?